Initialize the async jump variable with a smi to avoid polymorphic comparison.

runtime/vm/flow_graph_builder.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_FLOW_GRAPH_BUILDER_H_
 #define VM_FLOW_GRAPH_BUILDER_H_
 
 #include "platform/assert.h"
 #include "platform/globals.h"
 #include "vm/allocation.h"
@@ skipping 445 matching lines @@
                         const AbstractType& dst_type,
                         const String& dst_name);
 
   // Helpers for allocating and deallocating temporary locals on top of the
   // expression stack.
   LocalVariable* EnterTempLocalScope(Value* value);
   Definition* ExitTempLocalScope(LocalVariable* var);
 
   void BuildLetTempExpressions(LetNode* node);
 
-  void BuildAwaitJump(LocalScope* lookup_scope,
+  void BuildAwaitJump(LocalVariable* old_context,
+                      LocalVariable* continuation_result,
+                      LocalVariable* continuation_error,
                       const intptr_t old_ctx_level,
                       JoinEntryInstr* target);
 
   Isolate* isolate() const { return owner()->isolate(); }
 
  private:
   friend class TempLocalScope;  // For ReturnDefinition.
 
   // Helper to drop the result value.
   virtual void ReturnValue(Value* value) {
@@ skipping 121 matching lines @@
   // Output parameters.
   GrowableArray<TargetEntryInstr**> true_successor_addresses_;
   GrowableArray<TargetEntryInstr**> false_successor_addresses_;
 
   intptr_t condition_token_pos_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_BUILDER_H_