[PowerPC] Disable the CTR optimization in the presence of {min,max}num

The minnum and maxnum intrinsics get lowered to libcalls which
invalidates the CTR optimization.

This fixes PR27083.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264508 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed