error[E0658]: casting pointers to integers in constants is unstable
  --> $DIR/issue-52023-array-size-pointer-cast.rs:2:17
   |
LL |     let _ = [0; (&0 as *const i32) as usize];
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/51910
   = help: add #![feature(const_raw_ptr_to_usize_cast)] to the crate attributes to enable

error[E0080]: it is undefined behavior to use this value
  --> $DIR/issue-52023-array-size-pointer-cast.rs:2:17
   |
LL |     let _ = [0; (&0 as *const i32) as usize];
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected initialized plain (non-pointer) bytes
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0080, E0658.
For more information about an error, try `rustc --explain E0080`.