Revert "[PowerPC] Manually schedule the prologue and epilogue"

[PowerPC] This reverts commit r322036.

Failing build bots. Revert the commit now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322051 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed