warning: the feature `repr128` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/repr128.rs:2:12
   |
LL | #![feature(repr128, core_intrinsics, discriminant_kind)]
   |            ^^^^^^^
   |
   = note: `#[warn(incomplete_features)]` on by default
   = note: see issue #56071 <https://github.com/rust-lang/rust/issues/56071> for more information

warning: 1 warning emitted