Add optional timing logging for code completion results.  This causes a UDP packet containing the time taken for the code completion to be sent to a designated server (which is specified using a compile-time -D flag).
Add optional timing logging for code completion results.  This causes a UDP packet
containing the time taken for the code completion to be sent to a designated server
(which is specified using a compile-time -D flag).

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@101326 91177308-0d34-0410-b5e6-96231b3b80d8

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