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

[Yeoul Na via cfe-commits]

rapidsna wrote:

@AaronBallman As we discussed last time, I took the new approach to create a place holder type (LateParsedAttrType) and replace that with `CountAttributedType` upon late parsing. Please take a look.

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