[PowerPC] Fix test/CodeGen/ppc-sfvarargs
[PowerPC] Fix test/CodeGen/ppc-sfvarargs

The issue seems to be that .ll file may either use number of register
value or alias %numUsedRegs, so the check needs to cover both cases.

This will hopefully fix the last regression introduced by r255515.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@255539 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang