[llvm] [DirectX] Implement the ForwardHandleAccesses pass (PR #135378)

[Justin Bogner via llvm-commits]

bogner wrote:

@s-perron This pass would probably be better shared between the DXIL and SPIR-V backends like you're trying to do with #134260, but it's a bit awkward to do so since it needs to know two target specific things:
1. What a handle creation intrinsic looks like
2. What a resource handle global looks like

I suppose we could make it a generic pass and have some kind of target hook to get that information, but it's not obvious to me what that should look like. Do you have any ideas here?

https://github.com/llvm/llvm-project/pull/135378