Pass current thread as argument to alloc instrumentation.

Avoids recomputation in the hot allocation path when instrumentation is
enabled.

Change-Id: Ic6e7d7d0744f4756787f75d21fddd3c50280b588
diff --git a/runtime/gc/heap-inl.h b/runtime/gc/heap-inl.h
index d1fb600..c971449 100644
--- a/runtime/gc/heap-inl.h
+++ b/runtime/gc/heap-inl.h
@@ -140,7 +140,7 @@
   }
   if (kInstrumented) {
     if (Dbg::IsAllocTrackingEnabled()) {
-      Dbg::RecordAllocation(klass, bytes_allocated);
+      Dbg::RecordAllocation(self, klass, bytes_allocated);
     }
   } else {
     DCHECK(!Dbg::IsAllocTrackingEnabled());