[CodeGen][MIPS][NFC] Some standalone tests for D66805 "or vectors, select `add %x, C` as `sub %x, -C` if it results in inline immediate"
[CodeGen][MIPS][NFC] Some standalone tests for D66805 "or vectors, select `add %x, C` as `sub %x, -C` if it results in inline immediate"

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@372253 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm