Recommit r338204 "[X86] Correct the immediate cost for 'add/sub i64 %x, 0x80000000'."
Recommit r338204 "[X86] Correct the immediate cost for 'add/sub i64 %x, 0x80000000'."

This checks in a more direct way without triggering a UBSAN error.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@338273 91177308-0d34-0410-b5e6-96231b3b80d8

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