[clang] Turn 'counted_by' into a type attribute and parse it into 'CountAttributedType' (PR #78000)

[Yeoul Na via cfe-commits]

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@@ -7239,6 +7239,13 @@ QualType TreeTransform<Derived>::TransformAttributedType(TypeLocBuilder &TLB,
       });
 }
 
+template <typename Derived>
+QualType TreeTransform<Derived>::TransformCountAttributedType(
+    TypeLocBuilder &TLB, CountAttributedTypeLoc TL) {
+  // TODO
+  llvm_unreachable("Unexpected TreeTransform for CountAttributedType");
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rapidsna wrote:

@AaronBallman thanks for letting me know. I just implemented `TransformCountAttributedType`. I'll see if I can fine a test case to exercise this.

https://github.com/llvm/llvm-project/pull/78000