[llvm] [DirectX] Emit `hlsl.wavesize` function attribute as entry property metadata (PR #165624)

[Finn Plummer via llvm-commits]

inbelic wrote:

Looks like there is some custom handling that I missed from here: https://github.com/microsoft/DirectXShaderCompiler/blob/fa3fe957ea9656df75ce683c47fb2892151e4732/lib/DxilContainer/DxilContainerAssembler.cpp#L1536.

Looking to update it now. Thanks for catching that.

https://github.com/llvm/llvm-project/pull/165624