[clang] [llvm] [clang] Add spir_kernel attribute (PR #137882)

[Erich Keane via llvm-commits]

https://github.com/erichkeane commented:

I honestly really like the approach.  Those attributes really only differ by spelling and are almost semantically identical, so it makes a lot of sense to do it this way.  So I'm happy.

The accessors could be cleaned up, otherwise this is a LGTM.

https://github.com/llvm/llvm-project/pull/137882