Add more info to who called SuspendAll

Helps diagnose related jank.

Change-Id: I38191cdda723c6f0355d0197c494a3dff2b6653c
diff --git a/runtime/gc/space/rosalloc_space.cc b/runtime/gc/space/rosalloc_space.cc
index f140021..eb1d5f4 100644
--- a/runtime/gc/space/rosalloc_space.cc
+++ b/runtime/gc/space/rosalloc_space.cc
@@ -303,7 +303,7 @@
   // TODO: NO_THREAD_SAFETY_ANALYSIS.
   Thread* self = Thread::Current();
   ThreadList* tl = Runtime::Current()->GetThreadList();
-  tl->SuspendAll();
+  tl->SuspendAll(__FUNCTION__);
   {
     MutexLock mu(self, *Locks::runtime_shutdown_lock_);
     MutexLock mu2(self, *Locks::thread_list_lock_);