[clang] [clang][Sema] Add diagnostic note for reference of function-like macros requiring without parentheses (PR #123495)

[via cfe-commits]

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@@ -2509,6 +2509,20 @@ bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
     DC = DC->getLookupParent();
   }
 
+  // Check whether a similar function-like macro exists and suggest it
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Sirraide wrote:

Instead of doing this here before typo correction, the note that this pr adds should probably just be emitted right after the error we emit at the very end of this function (or after the one right before that we emit if the SS isn’t empty).

https://github.com/llvm/llvm-project/pull/123495