[llvm] [AMDGPU] Move AMDGPUTargetMachine into AMDGPUCodeGenPassBuilder(NFC) (PR #103720)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Certain options and static declarations are used between TM and TargetPassConfig. So moving CodeGenPassBuilder into AMDGPU TM is the viable option to avoid extern declarations of various common options.

Do you mean the few fields that use cl::location in the TargetMachine? I think we can just delete those at this point.

https://github.com/llvm/llvm-project/pull/103720