error[E0658]: `loop` is not allowed in a `const fn`
  --> $DIR/hir-const-check.rs:12:9
   |
LL |         loop {}
   |         ^^^^^^^
   |
   = note: see issue #52000 <https://github.com/rust-lang/rust/issues/52000> for more information
   = help: add `#![feature(const_loop)]` to the crate attributes to enable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0658`.