We don't test on very old versions of Apple platforms anymore. The
following lit substitution concerning the minimum deployment target for
ARC support can be removed.
```
%darwin_min_target_with_full_runtime_arc_support -> 10.11
```
Differential Revision: https://reviews.llvm.org/D85803
Objective-C's @synchronize synchronization primitive uses calls to objc_sync_enter and objc_sync_exit runtime functions. In most cases, they end up just calling pthread_mutex_lock/pthread_mutex_unlock, but there are some cases where the synchronization from pthread_mutex_lock/pthread_mutex_unlock interceptors isn't enough. Let's add explicit interceptors for objc_sync_enter and objc_sync_exit to handle all cases.
Differential Revision: https://reviews.llvm.org/D45487
llvm-svn: 329982
Julian Lettner