Implement async* functions in VM

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 449 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 BuildYieldJump(LocalVariable* old_context,
-                      LocalVariable* iterator_param,
-                      const intptr_t old_ctx_level,
-                      JoinEntryInstr* target);
+  void BuildSyncYieldJump(LocalVariable* old_context,
+                          LocalVariable* iterator_param,
+                          const intptr_t old_ctx_level,
+                          JoinEntryInstr* target);
+
+  void BuildAsyncYieldJump(LocalVariable* old_context,
+                           const intptr_t old_ctx_level,
+                           JoinEntryInstr* target);
 
   void BuildAwaitJump(LocalVariable* old_context,
                       LocalVariable* continuation_result,
                       LocalVariable* continuation_error,
                       LocalVariable* continuation_stack_trace,
                       const intptr_t old_ctx_level,
                       JoinEntryInstr* target);
 
   Isolate* isolate() const { return owner()->isolate(); }
 
@@ skipping 126 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_