Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

20 files changed, 451 insertions, 0 deletions

diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-construct.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-construct.js
new file mode 100644
index 0000000000..dbae1415b4
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-construct.js
@@ -0,0 +1,33 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-constructor
+description: >
+  %AsyncFunction% creates functions with or without new and handles arguments
+  similarly to functions.
+---*/
+
+var AsyncFunction = async function foo() {}.constructor;
+var fn;
+
+fn = AsyncFunction("a", "await 1;");
+assert.sameValue(fn.length, 1, "length with 1 argument, call");
+
+fn = AsyncFunction("a,b", "await 1;");
+assert.sameValue(fn.length, 2, "length with 2 arguments in one, call");
+
+fn = AsyncFunction("a", "b", "await 1;");
+assert.sameValue(fn.length, 2, "length with 2 arguments, call");
+
+fn = new AsyncFunction("a", "await 1;");
+assert.sameValue(fn.length, 1, "length with 1 argument, construct");
+
+fn = new AsyncFunction("a,b", "await 1;");
+assert.sameValue(fn.length, 2, "length with 2 arguments in one, construct");
+
+fn = new AsyncFunction("a", "b", "await 1;");
+assert.sameValue(fn.length, 2, "length with 2 arguments, construct");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-is-extensible.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-is-extensible.js
new file mode 100644
index 0000000000..a069166cd8
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-is-extensible.js
@@ -0,0 +1,15 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: pending
+description: >
+  %AsyncFunction% is extensible
+---*/
+
+var AsyncFunction = async function() {}.constructor;
+AsyncFunction.x = 1;
+assert.sameValue(AsyncFunction.x, 1);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-is-subclass.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-is-subclass.js
new file mode 100644
index 0000000000..ea84be36e5
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-is-subclass.js
@@ -0,0 +1,16 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-constructor
+description: >
+  %AsyncFunction% is a subclass of Function
+---*/
+async function foo() {};
+var AsyncFunction = foo.constructor;
+assert.sameValue(Object.getPrototypeOf(AsyncFunction), Function, "Prototype of constructor is Function");
+assert.sameValue(Object.getPrototypeOf(AsyncFunction.prototype), Function.prototype, "Prototype of constructor's prototype is Function.prototype");
+assert(foo instanceof Function, 'async function instance is instanceof Function');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-length.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-length.js
new file mode 100644
index 0000000000..03a0119a4e
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-length.js
@@ -0,0 +1,18 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-constructor-length
+description: >
+  %AsyncFunction% has a length of 1 with writable false, enumerable false, configurable true.
+includes: [propertyHelper.js]
+---*/
+
+var AsyncFunction = async function foo() {}.constructor;
+assert.sameValue(AsyncFunction.length, 1);
+verifyNotWritable(AsyncFunction, 'length');
+verifyNotEnumerable(AsyncFunction, 'length');
+verifyConfigurable(AsyncFunction, 'length');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-name.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-name.js
new file mode 100644
index 0000000000..b745e91a15
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-name.js
@@ -0,0 +1,18 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-constructor-properties
+description: >
+  %AsyncFunction% has a name of "AsyncFunction".
+includes: [propertyHelper.js]
+---*/
+
+var AsyncFunction = async function foo() {}.constructor;
+assert.sameValue(AsyncFunction.name, "AsyncFunction");
+verifyNotWritable(AsyncFunction, "name");
+verifyNotEnumerable(AsyncFunction, "name");
+verifyConfigurable(AsyncFunction, "name");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-prototype.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-prototype.js
new file mode 100644
index 0000000000..a8a2f2be9a
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction-prototype.js
@@ -0,0 +1,16 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-constructor-prototype
+description: AsyncFunction has a prototype property with writable false, enumerable false, configurable false.
+includes: [propertyHelper.js]
+---*/
+
+var AsyncFunction = async function foo() {}.constructor;
+verifyNotConfigurable(AsyncFunction, 'prototype');
+verifyNotWritable(AsyncFunction, 'prototype');
+verifyNotEnumerable(AsyncFunction, 'prototype');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction.js
new file mode 100644
index 0000000000..8d5207c2fa
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunction.js
@@ -0,0 +1,14 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-objects
+description: >
+  %AsyncFunction% exists and is a function
+---*/
+
+var AsyncFunction = async function foo() {}.constructor;
+assert.sameValue(typeof AsyncFunction, "function");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-is-extensible.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-is-extensible.js
new file mode 100644
index 0000000000..fecb464d08
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-is-extensible.js
@@ -0,0 +1,15 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-sync-function-prototype-properties
+description: >
+  %AsyncFunctionPrototype% has a [[Extensible]] of true
+---*/
+
+var AsyncFunction = async function foo() {}.constructor;
+AsyncFunction.prototype.x = 1;
+assert.sameValue(AsyncFunction.prototype.x, 1);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-is-not-callable.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-is-not-callable.js
new file mode 100644
index 0000000000..f3db773ba1
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-is-not-callable.js
@@ -0,0 +1,30 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-async-function-prototype-properties
+description: >
+  %AsyncFunction.prototype% is an ordinary non-callable object.
+info: |
+  Properties of the AsyncFunction Prototype Object
+
+  The AsyncFunction prototype object:
+
+  [...]
+  * is an ordinary object.
+  * is not a function object and does not have an [[ECMAScriptCode]] internal slot
+    or any other of the internal slots listed in Table 28.
+features: [async-functions]
+---*/
+
+var AsyncFunctionPrototype = Object.getPrototypeOf(async function() {});
+
+assert.sameValue(typeof AsyncFunctionPrototype, "object");
+assert.throws(TypeError, function() {
+  AsyncFunctionPrototype();
+});
+
+assert(!AsyncFunctionPrototype.hasOwnProperty("length"), "length");
+assert(!AsyncFunctionPrototype.hasOwnProperty("name"), "name");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-prototype.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-prototype.js
new file mode 100644
index 0000000000..f69dcf6a6a
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-prototype.js
@@ -0,0 +1,12 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-sync-function-prototype-properties
+description: AsyncFunction.prototype has a [[prototype]] of Function.prototype
+---*/
+var AsyncFunction = async function foo() {}.constructor;
+assert.sameValue(Object.getPrototypeOf(AsyncFunction.prototype), Function.prototype);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-to-string.js b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-to-string.js
new file mode 100644
index 0000000000..3aa8d3a4fa
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/AsyncFunctionPrototype-to-string.js
@@ -0,0 +1,20 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-prototype-properties-toStringTag
+description: >
+  %AsyncFunctionPrototype% has a Symbol.toStringTag property of "AsyncFunction"
+includes: [propertyHelper.js]
+features: [Symbol.toStringTag]
+---*/
+
+var AsyncFunction = async function foo() {}.constructor;
+var AFP = AsyncFunction.prototype;
+assert.sameValue(AFP[Symbol.toStringTag], "AsyncFunction", "toStringTag value");
+verifyNotWritable(AFP, Symbol.toStringTag);
+verifyNotEnumerable(AFP, Symbol.toStringTag);
+verifyConfigurable(AFP, Symbol.toStringTag);
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/browser.js b/js/src/tests/test262/built-ins/AsyncFunction/browser.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/browser.js
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/instance-construct-throws.js b/js/src/tests/test262/built-ins/AsyncFunction/instance-construct-throws.js
new file mode 100644
index 0000000000..e51c40a3e3
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/instance-construct-throws.js
@@ -0,0 +1,40 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-instances
+description: >
+  Async function instances are not constructors and do not have a
+  [[Construct]] slot.
+info: |
+    25.5.1.1 AsyncFunction( p1, p2, … , pn, body )
+
+    ...
+    3. Return CreateDynamicFunction(C, NewTarget, "async", args).
+
+    19.2.1.1.1 Runtime Semantics: CreateDynamicFunction( constructor, newTarget, kind, args )
+
+    ...
+    33. Perform FunctionInitialize(F, Normal, parameters, body, scope).
+    34. If kind is "generator", then
+        ...
+    35. Else if kind is "normal", perform MakeConstructor(F).
+    36. NOTE: Async functions are not constructable and do not have a [[Construct]] internal method
+        or a  "prototype" property.
+    ...
+---*/
+
+async function foo() {}
+assert.throws(TypeError, function() {
+  new foo();
+});
+
+var AsyncFunction = Object.getPrototypeOf(foo).constructor;
+var instance = AsyncFunction();
+
+assert.throws(TypeError, function() {
+  new instance();
+})
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/instance-has-name.js b/js/src/tests/test262/built-ins/AsyncFunction/instance-has-name.js
new file mode 100644
index 0000000000..13a6a8eb53
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/instance-has-name.js
@@ -0,0 +1,18 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-instances-name
+description: Async function declarations have a name property
+includes: [propertyHelper.js]
+---*/
+
+async function foo() {};
+
+assert.sameValue(foo.name, "foo");
+verifyNotWritable(foo, "name");
+verifyNotEnumerable(foo, "name");
+verifyConfigurable(foo, "name");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/instance-length.js b/js/src/tests/test262/built-ins/AsyncFunction/instance-length.js
new file mode 100644
index 0000000000..6a139180d6
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/instance-length.js
@@ -0,0 +1,24 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-instances-length
+description: >
+  Async functions have a length property that is the number of expected
+  arguments.
+includes: [propertyHelper.js]
+---*/
+
+async function l0() {}
+async function l1(a) {}
+async function l2(a, b) {}
+assert.sameValue(l0.length, 0);
+assert.sameValue(l1.length, 1);
+assert.sameValue(l2.length, 2)
+
+verifyNotWritable(l0, 'length');
+verifyNotEnumerable(l0, 'length');
+verifyConfigurable(l0, 'length');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/instance-prototype-property.js b/js/src/tests/test262/built-ins/AsyncFunction/instance-prototype-property.js
new file mode 100644
index 0000000000..74e17773f3
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/instance-prototype-property.js
@@ -0,0 +1,14 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-instances
+description: >
+  Async function instances do not have a prototype property.
+---*/
+async function foo() {};
+assert.sameValue(foo.prototype, undefined, 'foo.prototype should be undefined');
+assert(!foo.hasOwnProperty('prototype'), 'foo.prototype should not exist');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/is-a-constructor.js b/js/src/tests/test262/built-ins/AsyncFunction/is-a-constructor.js
new file mode 100644
index 0000000000..7730d8f081
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/is-a-constructor.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-ecmascript-standard-built-in-objects
+description: >
+  The AsyncFunction constructor implements [[Construct]]
+info: |
+  IsConstructor ( argument )
+
+  The abstract operation IsConstructor takes argument argument (an ECMAScript language value).
+  It determines if argument is a function object with a [[Construct]] internal method.
+  It performs the following steps when called:
+
+  If Type(argument) is not Object, return false.
+  If argument has a [[Construct]] internal method, return true.
+  Return false.
+includes: [isConstructor.js, hidden-constructors.js]
+features: [Reflect.construct]
+---*/
+
+assert.sameValue(isConstructor(AsyncFunction), true, 'isConstructor(AsyncFunction) must return true');
+new AsyncFunction();
+  
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/is-not-a-global.js b/js/src/tests/test262/built-ins/AsyncFunction/is-not-a-global.js
new file mode 100644
index 0000000000..97f167ce05
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/is-not-a-global.js
@@ -0,0 +1,15 @@
+// Copyright 2016 Microsoft, Inc. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Brian Terlson <brian.terlson@microsoft.com>
+esid: sec-async-function-constructor-properties
+description: >
+  %AsyncFunction% is not exposed as a global
+---*/
+
+assert.throws(ReferenceError, function() {
+  AsyncFunction
+}, "AsyncFunction should not be present as a global");
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/proto-from-ctor-realm.js b/js/src/tests/test262/built-ins/AsyncFunction/proto-from-ctor-realm.js
new file mode 100644
index 0000000000..780202a02a
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/proto-from-ctor-realm.js
@@ -0,0 +1,64 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-async-function-constructor-arguments
+description: Default [[Prototype]] value derived from realm of the NewTarget.
+info: |
+  AsyncFunction ( p1, p2, … , pn, body )
+
+  ...
+  3. Return CreateDynamicFunction(C, NewTarget, "async", args).
+
+  Runtime Semantics: CreateDynamicFunction ( constructor, newTarget, kind, args )
+
+  ...
+  9. Else if kind is "async", then
+    ...
+    c. Let fallbackProto be "%AsyncFunction.prototype%".
+  ...
+  18. Let proto be ? GetPrototypeFromConstructor(newTarget, fallbackProto).
+  ...
+
+  GetPrototypeFromConstructor ( constructor, intrinsicDefaultProto )
+
+  ...
+  3. Let proto be ? Get(constructor, "prototype").
+  4. If Type(proto) is not Object, then
+    a. Let realm be ? GetFunctionRealm(constructor).
+    b. Set proto to realm's intrinsic object named intrinsicDefaultProto.
+  5. Return proto.
+features: [async-functions, cross-realm, Reflect, Symbol]
+---*/
+
+var AsyncFunction = Object.getPrototypeOf(async function() {}).constructor;
+var other = $262.createRealm().global;
+var OtherAsyncFunction = Object.getPrototypeOf(other.eval('(0, async function() {})')).constructor;
+var newTarget = new other.Function();
+var fn;
+
+newTarget.prototype = undefined;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is undefined');
+
+newTarget.prototype = null;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is null');
+
+newTarget.prototype = true;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a Boolean');
+
+newTarget.prototype = '';
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a String');
+
+newTarget.prototype = Symbol();
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a Symbol');
+
+newTarget.prototype = 1;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a Number');
+
+reportCompare(0, 0);
diff --git a/js/src/tests/test262/built-ins/AsyncFunction/shell.js b/js/src/tests/test262/built-ins/AsyncFunction/shell.js
new file mode 100644
index 0000000000..7af18bddd7
--- /dev/null
+++ b/js/src/tests/test262/built-ins/AsyncFunction/shell.js
@@ -0,0 +1,43 @@
+// GENERATED, DO NOT EDIT
+// file: hidden-constructors.js
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: |
+  Provides uniform access to built-in constructors that are not exposed to the global object.
+defines:
+  - AsyncArrowFunction
+  - AsyncFunction
+  - AsyncGeneratorFunction
+  - GeneratorFunction
+---*/
+
+var AsyncArrowFunction = Object.getPrototypeOf(async () => {}).constructor;
+var AsyncFunction = Object.getPrototypeOf(async function () {}).constructor;
+var AsyncGeneratorFunction = Object.getPrototypeOf(async function* () {}).constructor;
+var GeneratorFunction = Object.getPrototypeOf(function* () {}).constructor;
+
+// file: isConstructor.js
+// Copyright (C) 2017 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: |
+    Test if a given function is a constructor function.
+defines: [isConstructor]
+features: [Reflect.construct]
+---*/
+
+function isConstructor(f) {
+    if (typeof f !== "function") {
+      throw new Test262Error("isConstructor invoked with a non-function value");
+    }
+
+    try {
+        Reflect.construct(function(){}, [], f);
+    } catch (e) {
+        return false;
+    }
+    return true;
+}