[PowerPC][NFC] Add tests for some missed optimization opportunities in combineSetCC
[PowerPC][NFC] Add tests for some missed optimization opportunities in combineSetCC

For both operands are bool, short, int, long, long long, add the following optimization test case.
1. 0-x == y --> x+y ==0
2. 0-x != y --> x+y != 0

Review: nemanjai
Differential Revision: https://reviews.llvm.org/D53358


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@345357 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm