Forward-declare NSRecursiveLock, not NSLock

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/performance/trunk@38168 72102866-910b-0410-8b05-ffd578937521
Import inttypes.h for pointer formatting

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/performance/trunk@38169 72102866-910b-0410-8b05-ffd578937521