[clang] [clang][Sema] Suggest/Hint Standard Library Include File (PR #146227)

[Erich Keane via cfe-commits]

================
@@ -554,6 +563,11 @@ bool Parser::ParseOptionalCXXScopeSpecifier(
     break;
   }
 
+  if (FailedNesatedNameBuilding && Tok.getKind() == tok::identifier) {
----------------
erichkeane wrote:

Parser isn't really the right place to do this.  This is very much a 'sema' diagnostic/suggestion.  This should happen not here, but on failed lookup.

https://github.com/llvm/llvm-project/pull/146227