Remove the need to cache the subtarget in the PowerPC TargetRegisterInfo
classes. Replace it with a cache to the TargetMachine and use that
where applicable at the moment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232002 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed