[clang] [llvm] [opt][AMDGPU] Add pass to handle AMDGCN pseudo-intrinsics target specific info), start with `llvm.amdgcn.wavefrontsize` (PR #114481)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> As per my other reply, this is not an invalid use case, but somewhat niche. We can have a control value for disabling this early fold, for such builds, to avoid the need to do two builds (which might also be fine for `libc`). I don't think ROCDL uses the intrinsic at all.

ROCDL does something worse IMO, which is linking in a magic global constant instead of just using an intrinsic. I figured it would be safe to check if the caller has target attributes at all, but apparently `+wavefrontsize32` on the function isn't enough as per Matt's reply.

https://github.com/llvm/llvm-project/pull/114481