[clang] [llvm] [clang][DebugInfo] Emit DW_AT_object_pointer on function declarations with explicit `this` (PR #122928)

[Michael Buch via llvm-commits]

Michael137 wrote:

Will be rebased on top of https://github.com/llvm/llvm-project/pull/122897

https://github.com/llvm/llvm-project/pull/122928