[clang] [Clang][HLSL] Add environment parameter to availability attribute (PR #89809)

[Chris B via cfe-commits]

https://github.com/llvm-beanz commented:

Overall I really like the direction of this. I'm curious if any of the maintainers from Apple have thoughts since they're the primary users of availability annotations.

I think this dramatically simplifies things for what we need, but it might also have some benefits to be able to simplify how Apple expresses some of its existing annotations.

(cc @cyndyishida 👋 )

https://github.com/llvm/llvm-project/pull/89809