[clang] [llvm] [llvm][DebugInfo] Add new DW_AT_APPLE_enum_kind to encode enum_extensibility (PR #124752)

[Michael Buch via cfe-commits]

Michael137 wrote:

I've only included the LLVM changes here now (anything metadata and DWARF attribute related). Will do the plumbing from the frontend in a separate patch

https://github.com/llvm/llvm-project/pull/124752