Change the AppleObjCTrampolineHandler to always run all threads when resolving...

Change the AppleObjCTrampolineHandler to always run all threads when resolving the target of an ObjC method call.
Add a StopOthers method to AppleThreadPlanStepThroughObjCTrampoline, don't rely on the setting in the ThreadPlanToCallFunction, since that
gets pushed too late to determine which threads will continue.

<rdar://problem/13447638>

llvm-svn: 177691