Introduce a nesting stack to the flow graph builder.

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 815 matching lines @@
              SourceLabel* label,
              SequenceNode* body)
     : AstNode(token_pos),
       label_(label),
       body_(body) {
     ASSERT(label_ != NULL);
     ASSERT(body_ != NULL);
   }
 
   SourceLabel* label() const { return label_; }
-  AstNode* body() const { return body_; }
+  SequenceNode* body() const { return body_; }
 
   virtual void VisitChildren(AstNodeVisitor* visitor) const {
     body()->Visit(visitor);
   }
 
   DECLARE_COMMON_NODE_FUNCTIONS(SwitchNode);
 
  private:
   SourceLabel* label_;
-  AstNode* body_;
+  SequenceNode* body_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(SwitchNode);
 };
 
 
 class WhileNode : public AstNode {
  public:
   WhileNode(intptr_t token_pos,
             SourceLabel* label,
             AstNode* condition,
@@ skipping 115 matching lines @@
  public:
   JumpNode(intptr_t token_pos,
            Token::Kind kind,
            SourceLabel* label)
     : AstNode(token_pos),
       kind_(kind),
       label_(label),
       inlined_finally_list_() {
     ASSERT(label_ != NULL);
     ASSERT(kind_ == Token::kBREAK || kind_ == Token::kCONTINUE);
-    if (kind_ == Token::kCONTINUE) {
-      label_->set_is_continue_target(true);
-    }
   }
 
   SourceLabel* label() const { return label_; }
   Token::Kind kind() const { return kind_; }
 
   intptr_t inlined_finally_list_length() const {
     return inlined_finally_list_.length();
   }
   InlinedFinallyNode* InlinedFinallyNodeAt(intptr_t index) const {
     return inlined_finally_list_[index];
@@ skipping 778 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_