Add note to address check_match errors

Author: estebank

src/librustc_mir/build/matches/mod.rs

@@ -439,9 +439,9 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
         self.simplify_candidate(&mut candidate);
 
         if !candidate.match_pairs.is_empty() {
-            // Only abort compilation if no other errors have been emitted. This used to be a hard
-            // error that wouldn't be reached because `hair::pattern::check_match::check_match`
-            // wouldn't have let the compiler continue. In our tests this is only ever hit by
+            // ICE if no other errors have been emitted. This used to be a hard error that wouldn't
+            // be reached because `hair::pattern::check_match::check_match` wouldn't have let the
+            // compiler continue. In our tests this is only ever hit by
             // `ui/consts/const-match-check.rs` with `--cfg eval1`, and that file already generates
             // a different error before hand.
             self.hir.tcx().sess.delay_span_bug(

src/librustc_mir/const_eval.rs

@@ -618,6 +618,7 @@ pub fn const_eval_raw_provider<'a, 'tcx>(
         let tables = tcx.typeck_tables_of(def_id);
 
         // Do match-check before building MIR
+        // FIXME(#59378) check_match may have errored but we're not checking for that anymore
         tcx.check_match(def_id);
 
         if let hir::BodyOwnerKind::Const = tcx.hir().body_owner_kind_by_hir_id(id) {