[PowerPC] Change assert to better form

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220092 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "TRE: make TRE a bit more aggressive"

This reverts commit r219899.

This also updates byval-tail-call.ll to make it clear what was breaking.
Adding r219899 again will cause the load/store to disappear.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220093 91177308-0d34-0410-b5e6-96231b3b80d8
[PowerPC] Disable +vsx RUN line for fma.ll due to inconsistency on other builders

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220094 91177308-0d34-0410-b5e6-96231b3b80d8