Validate DiagGroup names in TableGen, they're used as command line arguments so we don't want shell meta chars in there.
Validate DiagGroup names in TableGen, they're used as command line arguments so we don't want shell meta chars in there.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@144645 91177308-0d34-0410-b5e6-96231b3b80d8

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