[clang] [ObjC] Fix Assertion failure when merging declarations with different lifetime qualifiers (PR #203272)

[Hendrik Hübner via cfe-commits]

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@@ -12356,7 +12356,8 @@ QualType ASTContext::mergeObjCGCQualifiers(QualType LHS, QualType RHS) {
   if (LQuals != RQuals) {
     // If any of these qualifiers are different, we have a type mismatch.
     if (LQuals.getCVRQualifiers() != RQuals.getCVRQualifiers() ||
-        LQuals.getAddressSpace() != RQuals.getAddressSpace())
+        LQuals.getAddressSpace() != RQuals.getAddressSpace() ||
+        LQuals.getObjCLifetime() != RQuals.getObjCLifetime())
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HendrikHuebner wrote:

@ahatanak Good point. I updated the logic to fail the merge step whenever anything but the GC qualifiers are unequal.

https://github.com/llvm/llvm-project/pull/203272