only do one DenseMap lookup instead of two (one to find out if there is already an entry and one to insert).
only do one DenseMap lookup instead of two (one to find out if there is
already an entry and one to insert).


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@65030 91177308-0d34-0410-b5e6-96231b3b80d8

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