[clang] [clang]: support std::meta::info for primitive types (PR #190356)

[Daniel M. Katz via cfe-commits]

================
@@ -18517,6 +18560,23 @@ EvaluateComparisonBinaryOperator(EvalInfo &Info, const BinaryOperator *E,
     return Success(CmpResult::Equal, E);
   }
 
+  if (LHSTy->isMetaInfoType() && RHSTy->isMetaInfoType()) {
+    APValue LHSValue, RHSValue;
+    llvm::FoldingSetNodeID LID, RID;
+    if (!Evaluate(LHSValue, Info, E->getLHS()))
+      return false;
+    LHSValue.Profile(LID);
+
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katzdm wrote:

Sorry, I meant `getFirstDecl()`; I had forgotten that "first" isn't necessarily "canonical". Agreed; `getFirstDecl()` seems like the way to go.

You could probably find a few bugs in my fork from my confusion of the two lol

https://github.com/llvm/llvm-project/pull/190356