Rollup merge of #118358 - RalfJung:const-tests, r=WaffleLapkin

make const tests independent of std debug assertions

Fixes some fallout from #110303: `ignore-debug` is bad since it makes it very annoying to develop rustc with debug assertions enabled.

These tests do not really provide any interesting test coverage, we already got plenty of other tests that check that we detect invalid enums. So we can just remove them.

Author: TaKO8Ki

tests/ui/consts/const-eval/raw-bytes.32bit.stderr

@@ -1,7 +1,6 @@
 // stderr-per-bitwidth
 // ignore-endian-big
 // ignore-tidy-linelength
-// ignore-debug debug assertions catch some UB too early
 // normalize-stderr-test "╾─*ALLOC[0-9]+(\+[a-z0-9]+)?─*╼" -> "╾ALLOC_ID$1╼"
 
 #![feature(never_type, rustc_attrs, ptr_metadata, slice_from_ptr_range, const_slice_from_ptr_range)]
@@ -13,6 +12,8 @@ use std::ptr::NonNull;
 use std::num::{NonZeroU8, NonZeroUsize};
 use std::slice::{from_ptr_range, from_raw_parts};
 
+// # Bad enums and chars
+
 #[repr(usize)]
 #[derive(Copy, Clone)]
 enum Enum {
@@ -51,6 +52,7 @@ const BAD_UNINHABITED_VARIANT2: UninhDiscriminant = unsafe { mem::transmute(3u8)
 const BAD_OPTION_CHAR: Option<(char, char)> = Some(('x', unsafe { mem::transmute(!0u32) }));
 //~^ ERROR is undefined behavior
 
+// # Bad pointers and references
 
 const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
 //~^ ERROR it is undefined behavior to use this value
@@ -197,16 +199,7 @@ const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92
 const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) };
 //~^ ERROR it is undefined behavior to use this value
 
-
-// not ok, since alignment needs to be non-zero.
-const LAYOUT_INVALID_ZERO: Layout = unsafe { Layout::from_size_align_unchecked(0x1000, 0x00) };
-//~^ ERROR it is undefined behavior to use this value
-
-// not ok, since alignment needs to be a power of two.
-const LAYOUT_INVALID_THREE: Layout = unsafe { Layout::from_size_align_unchecked(9, 3) };
-//~^ ERROR it is undefined behavior to use this value
-
-
+// Uninhabited types
 const _: &[!; 1] = unsafe { &*(1_usize as *const [!; 1]) }; //~ ERROR undefined behavior
 const _: &[!] = unsafe { &*(1_usize as *const [!; 1]) }; //~ ERROR undefined behavior
 const _: &[!] = unsafe { &*(1_usize as *const [!; 42]) }; //~ ERROR undefined behavior