[clang] [clang][DebugInfo] Emit DW_AT_object_pointer on function definitions with explicit `this` (PR #122897)

[Michael Buch via cfe-commits]

Michael137 wrote:

@dwblaikie @adrian-prantl any thoughts on adjusting the DWARF spec to allow explicit `this` parameters to be non-artificial but still be valid `DW_AT_object_pointer`s?

https://github.com/llvm/llvm-project/pull/122897