Enable await in for and for-in loops.

runtime/vm/ast.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_AST_H_
 #define VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
@@ skipping 1015 matching lines @@
 };
 
 
 // The condition can be NULL.
 class ForNode : public AstNode {
  public:
   ForNode(intptr_t token_pos,
           SourceLabel* label,
           SequenceNode* initializer,
           AstNode* condition,
+          SequenceNode* condition_preamble,
           SequenceNode* increment,
           SequenceNode* body)
     : AstNode(token_pos),
       label_(label),
       initializer_(initializer),
       condition_(condition),
+      condition_preamble_(condition_preamble),
       increment_(increment),
       body_(body) {
     ASSERT(label_ != NULL);
     ASSERT(initializer_ != NULL);
     ASSERT(increment_ != NULL);
     ASSERT(body_ != NULL);
   }
 
   SourceLabel* label() const { return label_; }
   SequenceNode* initializer() const { return initializer_; }
   AstNode* condition() const { return condition_; }
+  AstNode* condition_preamble() const { return condition_preamble_; }
   SequenceNode* increment() const { return increment_; }
   SequenceNode* body() const { return body_; }
 
   virtual void VisitChildren(AstNodeVisitor* visitor) const {
     initializer()->Visit(visitor);
+    if (condition_preamble() != NULL) {
+      ASSERT(condition() != NULL);
+      condition_preamble()->Visit(visitor);
+    }
     if (condition() != NULL) {
       condition()->Visit(visitor);
     }
     increment()->Visit(visitor);
     body()->Visit(visitor);
   }
 
   DECLARE_COMMON_NODE_FUNCTIONS(ForNode);
 
  private:
   SourceLabel* label_;
   SequenceNode* initializer_;
   AstNode* condition_;
+  AstNode* condition_preamble_;
   SequenceNode* increment_;
   SequenceNode* body_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(ForNode);
 };
 
 
 class JumpNode : public AstNode {
  public:
   JumpNode(intptr_t token_pos,
@@ skipping 824 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_