error[E0658]: C-cmse-nonsecure-call ABI is experimental and subject to change
  --> $DIR/gate_test.rs:5:46
   |
LL |         core::mem::transmute::<usize, extern "C-cmse-nonsecure-call" fn(i32, i32, i32, i32) -> i32>(
   |                                              ^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #81391 <https://github.com/rust-lang/rust/issues/81391> for more information
   = help: add `#![feature(abi_c_cmse_nonsecure_call)]` to the crate attributes to enable
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error: aborting due to 1 previous error

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