[clang] [BoundsSafety] Support bounds-safety attributes in type positions (PR #179612)

[Hans Wennborg via cfe-commits]

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@@ -44,6 +44,14 @@ let Class = CountAttributedType in {
   def : Creator<[{ return ctx.getCountAttributedType(WrappedTy, CountExpr, CountInBytes, OrNull, CoupledDecls); }]>;
 }
 
+let Class = LateParsedAttrType in {
+  // Note: LateParsedAttrType is a transient placeholder type that should
+  // normally be replaced before serialization. If serialized, we just
+  // serialize the wrapped type, losing the late-parsed attribute pointer
+  // (which wouldn't be valid after deserialization anyway).
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zmodem wrote:

Isn't it enough to say this won't be serialized (because it should have been replaced before that), given that it's marked `llvm_unreachable`?

https://github.com/llvm/llvm-project/pull/179612