Only call TryAnnotateScopeToken when parsing C++.  - This improves -parse-noop of Carbon.h by +2%, and I believe    compensates for the majority of the performance regression in r58913.
Only call TryAnnotateScopeToken when parsing C++.
 - This improves -parse-noop of Carbon.h by +2%, and I believe
   compensates for the majority of the performance regression in r58913.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@60063 91177308-0d34-0410-b5e6-96231b3b80d8

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