[clang] [HLSL] Fix resource wrapper declaration (PR #125718)

[Steven Perron via cfe-commits]

s-perron wrote:

The other option is https://github.com/llvm/llvm-project/pull/123811. However, can you clarify "separate compilation". It is not clear to me exactly what type of linking you have in mind. This make it hard for me to reason about what should be done, and when.

Are you thinking of linking multiple llvm-ir modules or SPIR-V modules? Are there calls to functions in other modules or does each module have it owns self contained entry points?

https://github.com/llvm/llvm-project/pull/125718