[analyzer] scan-build: match whitespace instead of word boundaries around flags.
[analyzer] scan-build: match whitespace instead of word boundaries around flags.

Because neither ' ' nor '-' is alphanumeric, \b won't match between them!
Since in this case we know our output is coming from a -### invocation,
we should always have spaces on both sides of the flag we're trying to match,
"-cc1".

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@204356 91177308-0d34-0410-b5e6-96231b3b80d8

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