Don't bother running the analysis for CFG-based warnings if the declaration is in a system header.
Don't bother running the analysis for CFG-based warnings if the
declaration is in a system header.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@99087 91177308-0d34-0410-b5e6-96231b3b80d8

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