[clang] [Clang][OpenCL][AMDGPU] Use `byref` for OpenCL kernel arguments (PR #134892)

[Matt Arsenault via cfe-commits]

arsenm wrote:

> I might misunderstand it but based on your comment, it doesn't sound like the issue is with using `byref` for aggregate arguments in OpenCL (which is what this PR is trying to do), especially since OpenCL is currently the only language not using it. We already use it for HIP.

Oh, this issue is just for only using byref for all arguments (which is what we should eventually do)


https://github.com/llvm/llvm-project/pull/134892