Rollup merge of #75587 - RalfJung:mir-comment-fixes, r=ecstatic-morse

mir building: fix some comments

r? @oli-obk

At least I hope these fixes are right, please double-check.^^

src/librustc_mir/transform/mod.rs

@@ -321,6 +321,7 @@ fn mir_validated(
 
     // Ensure that we compute the `mir_const_qualif` for constants at
     // this point, before we steal the mir-const result.
+    // Also this means promotion can rely on all const checks having been done.
     let _ = tcx.mir_const_qualif_opt_const_arg(def);
 
     let mut body = tcx.mir_const(def).steal();
@@ -336,7 +337,7 @@ fn mir_validated(
     let promote: &[&dyn MirPass<'tcx>] = &[
         // What we need to run borrowck etc.
         &promote_pass,
-        &simplify::SimplifyCfg::new("qualify-consts"),
+        &simplify::SimplifyCfg::new("promote-consts"),
     ];
 
     let opt_coverage: &[&dyn MirPass<'tcx>] = if tcx.sess.opts.debugging_opts.instrument_coverage {

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

@@ -14,7 +14,7 @@ trait Foo {
 }
 
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
-// EMIT_MIR issue_41697.{{impl}}-{{constant}}.SimplifyCfg-qualify-consts.after.mir
+// EMIT_MIR issue_41697.{{impl}}-{{constant}}.SimplifyCfg-promote-consts.after.mir
 impl Foo for [u8; 1+1] {
     fn get(&self) -> [u8; 2] {
         *self

src/test/mir-opt/issue_41697.{{impl}}-{{constant}}.SimplifyCfg-qualify-consts.after.mir.32bit → src/test/mir-opt/issue_41697.{{impl}}-{{constant}}.SimplifyCfg-promote-consts.after.mir.32bit

-// MIR for `<impl at $DIR/issue-41697.rs:18:1: 22:2>::{{constant}}#0` after SimplifyCfg-qualify-consts
+// MIR for `<impl at $DIR/issue-41697.rs:18:1: 22:2>::{{constant}}#0` after SimplifyCfg-promote-consts
 
 <impl at $DIR/issue-41697.rs:18:1: 22:2>::{{constant}}#0: usize = {
     let mut _0: usize;                   // return place in scope 0 at $DIR/issue-41697.rs:18:19: 18:22

src/test/mir-opt/issue_41697.{{impl}}-{{constant}}.SimplifyCfg-qualify-consts.after.mir.64bit → src/test/mir-opt/issue_41697.{{impl}}-{{constant}}.SimplifyCfg-promote-consts.after.mir.64bit

-// MIR for `<impl at $DIR/issue-41697.rs:18:1: 22:2>::{{constant}}#0` after SimplifyCfg-qualify-consts
+// MIR for `<impl at $DIR/issue-41697.rs:18:1: 22:2>::{{constant}}#0` after SimplifyCfg-promote-consts
 
 <impl at $DIR/issue-41697.rs:18:1: 22:2>::{{constant}}#0: usize = {
     let mut _0: usize;                   // return place in scope 0 at $DIR/issue-41697.rs:18:19: 18:22

src/test/mir-opt/loop_test.main.SimplifyCfg-qualify-consts.after.mir → src/test/mir-opt/loop_test.main.SimplifyCfg-promote-consts.after.mir

-// MIR for `main` after SimplifyCfg-qualify-consts
+// MIR for `main` after SimplifyCfg-promote-consts
 
 fn main() -> () {
     let mut _0: ();                      // return place in scope 0 at $DIR/loop_test.rs:6:11: 6:11

src/test/mir-opt/loop_test.rs

@@ -2,7 +2,7 @@
 
 // Tests to make sure we correctly generate falseUnwind edges in loops
 
-// EMIT_MIR loop_test.main.SimplifyCfg-qualify-consts.after.mir
+// EMIT_MIR loop_test.main.SimplifyCfg-promote-consts.after.mir
 fn main() {
     // Exit early at runtime. Since only care about the generated MIR
     // and not the runtime behavior (which is exercised by other tests)