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

This reverts commit r322124 since some tests were broken by that patch.
Will recommmit once the patch is fixed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322369 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed