[llvm] [AMDGPU] make AMDGPUUniformIntrinsicCombine a function pass (PR #165265)

[Sameer Sahasrabuddhe via llvm-commits]

https://github.com/ssahasra approved this pull request.

LGTM, except for the nit about `eraseFromParent()`. It will be good to keep the erase if that is legal. Also please wait a day for @arsenm to comment.

https://github.com/llvm/llvm-project/pull/165265