[clang] [HLSL] Avoid putting ByVal on out and inout parameters (PR #150495)

[Deric C. via cfe-commits]

Icohedron wrote:

> Is it worth adding a test that would have added DeadOnReturn attribute, but now doesn't? Or is that covered by plenty of other tests currently?

I don't know in what cases a DeadOnReturn attribute would be added in HLSL, so I'm not sure how to write a test for that.

https://github.com/llvm/llvm-project/pull/150495