[PowerPC] Use sync inst alias when printing

So long as the choice between printing msync and sync is not ambiguous, we can
print 'sync 0' and just 'sync'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235663 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed