[NFC][lit] Use proper semantic versioning names for variables
[NFC][lit] Use proper semantic versioning names for variables

The variable named `minor` was actually pointing to the patch part of
the version. While I was changing this I also made the check for Apple
clang more robust by checking both patch and minor rather than just
minor.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@319656 91177308-0d34-0410-b5e6-96231b3b80d8

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