Rollup merge of #101435 - JakobDegen:bitwidth-tests, r=wesleywiser

Remove unnecessary `EMIT_MIR_FOR_EACH_BITWIDTH`

This commit removes the annotation only for those tests where the 32 bit and 64 bit files were exactly identical. I didn't touch anything in the `mir-opt/const` directory, since having this annotation there seems more principled, even if it doesn't make a difference.

This also removes four additional files related to the `separate_const_switch.rs` test. The associated annotations were removed in #100827 , but I forgot to remove the files as well. (#97564 is the issue tracking an automated check here)

r? ```@wesleywiser```

src/test/mir-opt/array-index-is-temporary.rs

@@ -7,7 +7,7 @@ unsafe fn foo(z: *mut usize) -> u32 {
     99
 }
 
-// EMIT_MIR_FOR_EACH_BIT_WIDTH
+
 // EMIT_MIR array_index_is_temporary.main.SimplifyCfg-elaborate-drops.after.mir
 fn main() {
     let mut x = [42, 43, 44];

src/test/mir-opt/inline/inline-into-box-place.rs

@@ -1,7 +1,7 @@
 // ignore-endian-big
 // ignore-wasm32-bare compiled with panic=abort by default
 // compile-flags: -Z mir-opt-level=4
-// EMIT_MIR_FOR_EACH_BIT_WIDTH
+
 #![feature(box_syntax)]
 // EMIT_MIR inline_into_box_place.main.Inline.diff
 fn main() {

src/test/mir-opt/issue-41697.rs

@@ -13,7 +13,7 @@ trait Foo {
     fn get(&self) -> [u8; 2];
 }
 
-// EMIT_MIR_FOR_EACH_BIT_WIDTH
+
 // EMIT_MIR issue_41697.{impl#0}-{constant#0}.SimplifyCfg-promote-consts.after.mir
 impl Foo for [u8; 1+1] {
     fn get(&self) -> [u8; 2] {

src/test/mir-opt/issue-72181.rs

@@ -11,14 +11,14 @@ union Foo {
     b: Never
 }
 
-// EMIT_MIR_FOR_EACH_BIT_WIDTH
+
 // EMIT_MIR issue_72181.foo.mir_map.0.mir
 fn foo(xs: [(Never, u32); 1]) -> u32 { xs[0].1 }
 
 // EMIT_MIR issue_72181.bar.mir_map.0.mir
 fn bar([(_, x)]: [(Never, u32); 1]) -> u32 { x }
 
-// EMIT_MIR_FOR_EACH_BIT_WIDTH
+
 // EMIT_MIR issue_72181.main.mir_map.0.mir
 fn main() {
     let _ = mem::size_of::<Foo>();

src/test/mir-opt/issue-73223.rs

@@ -8,5 +8,5 @@ fn main() {
     assert_eq!(split, 1);
 }
 
-// EMIT_MIR_FOR_EACH_BIT_WIDTH
+
 // EMIT_MIR issue_73223.main.SimplifyArmIdentity.diff