Fixed a VC++ issue related to bitmasks. As it turns out the compiler fills the unused bits of the word a bitmask is stored in with '1' (or randomly, I can't tell, I've seen '1' so far only), which creates wrong results in certain cases.
Fixed a VC++ issue related to bitmasks. As it turns out the compiler fills the unused bits of the word a bitmask is stored in with '1' (or randomly, I can't tell, I've seen '1' so far only), which creates wrong results in certain cases.

Please review.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@42061 91177308-0d34-0410-b5e6-96231b3b80d8

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