Revert "[PowerPC] Try to simplify a Swap if it feeds a Splat"

Revert r316478.
A test case has failed.
Will recommit this change once we find and fix the failure.

This reverts commit 7c330fabaedaba3d02c58bc3cc1198896c895f34.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316952 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed