Loosen checks for _MSC_FULL_VER under -fms-extensions.
Loosen checks for _MSC_FULL_VER under -fms-extensions.

Summary:
On actual Windows hosts :-) , this could report something other than the
fallback, with a non-zero minor/build number.

Reviewers: rnk, llvm-commits

Differential Revision: https://reviews.llvm.org/D27554

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@289011 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang