[llvm] AMDGPU/GlobalISel: Implement RegBankLegalizeRules for amdgcn_log, amdgcn_rcp, and amdgcn_sqrt (PR #195099)

[Petar Avramovic via llvm-commits]

petar-avramovic wrote:

there is for example llvm/test/CodeGen/AMDGPU/llvm.amdgcn.log.ll, some tests should be already present there

https://github.com/llvm/llvm-project/pull/195099