[llvm] [mlir] [TableGen] Split *GenRegisterInfo.inc. (PR #167700)

[Ivan Kosarev via llvm-commits]

kosarev wrote:

> ```shell
> $ ninja llc # works
> $ rm lib/Target/AMDGPU/AMDGPUGenRegisterInfo.inc && ninja llc # works
> $ rm lib/Target/AMDGPU/AMDGPUGenRegisterInfoEnums.inc && ninja llc # fails!
> ```

Addressed in https://github.com/llvm/llvm-project/pull/168405.

https://github.com/llvm/llvm-project/pull/167700