Fixed slow path for invoke-direct with null this pointer.

Moved the null pointer check until after the class linker tries to
resolve the method on the slow path.

Change-Id: Ie0f9e279a98a7e3a40899fee92337ef454c9a468
diff --git a/src/runtime_support.h b/src/runtime_support.h
index d0a6209..adeedb7 100644
--- a/src/runtime_support.h
+++ b/src/runtime_support.h
@@ -223,7 +223,7 @@
   }
 }
 
-extern AbstractMethod* FindMethodFromCode(uint32_t method_idx, Object* this_object, const AbstractMethod* referrer,
+extern AbstractMethod* FindMethodFromCode(uint32_t method_idx, Object* this_object, AbstractMethod* referrer,
                                   Thread* self, bool access_check, InvokeType type)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);