scripted-diff: Replace CCriticalSection with RecursiveMutex

-BEGIN VERIFY SCRIPT-
 # Delete outdated alias for RecursiveMutex
 sed -i -e '/CCriticalSection/d'                 ./src/sync.h
 # Replace use of outdated alias with RecursiveMutex
 sed -i -e 's/CCriticalSection/RecursiveMutex/g' $(git grep -l CCriticalSection)
-END VERIFY SCRIPT-

src/sync.h

@@ -106,7 +106,6 @@ public:
  * TODO: We should move away from using the recursive lock by default.
  */
 using RecursiveMutex = AnnotatedMixin<std::recursive_mutex>;
-typedef AnnotatedMixin<std::recursive_mutex> CCriticalSection;
 
 /** Wrapped mutex: supports waiting but not recursive locking */
 typedef AnnotatedMixin<std::mutex> Mutex;