[clang] [lldb] [clang] Add `__ptrauth_restricted_intptr` qualifier (PR #137580)

[Oliver Hunt via cfe-commits]

ojhunt wrote:

@AaronBallman have you made a decision? (if the keyword has to go away I need to replace all the tests and work out how to integrate with other libraries downstream in a way that works in both modes)

https://github.com/llvm/llvm-project/pull/137580