[clang] [BoundsSafety][Sema] Allow counted_by and counted_by_or_null on pointers where the pointee type is incomplete but potentially completable (PR #106321)

[Henrik G. Olsson via cfe-commits]

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@@ -186,4 +218,370 @@ bool Sema::CheckCountedByAttrOnField(FieldDecl *FD, Expr *E, bool CountInBytes,
   return false;
 }
 
+SourceRange Sema::BoundsSafetySourceRangeFor(const CountAttributedType *CATy) {
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hnrklssn wrote:

[#108631](https://github.com/llvm/llvm-project/pull/108631) seems to have similar issues with wanting to access `AttributedTypeLoc` when all they have is `AttributedType`. We might need to improve the infrastructure for accessing `TypeLoc`s in a more ergonomic fashion.

https://github.com/llvm/llvm-project/pull/106321