Fix the MSVC version check.
Fix the MSVC version check.

I'm not sure what determines the minor version, but it appears
that it's possible for a fully updated, release version of
VS2015 with Update 3 can go (at least) as low as 19.00.24213.1.
Updating the compiler version check to account for this so we
don't generate superfluous warnings.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@290914 91177308-0d34-0410-b5e6-96231b3b80d8

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