Remove unused code for StringConcatNode from the AST and the graph builder.

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"
 #include "vm/scopes.h"
 #include "vm/object.h"
 #include "vm/native_entry.h"
 #include "vm/token.h"
 
 namespace dart {
 
 #define NODE_LIST(V)                                                           \
   V(ReturnNode, "return")                                                      \
   V(LiteralNode, "literal")                                                    \
   V(TypeNode, "type")                                                          \
   V(AssignableNode, "assignable")                                              \
   V(BinaryOpNode, "binop")                                                     \
-  V(StringConcatNode, "concat")                                                \
   V(ComparisonNode, "compare")                                                 \
   V(UnaryOpNode, "unaryop")                                                    \
   V(ConditionalExprNode, "?:")                                                 \
   V(IfNode, "if")                                                              \
   V(SwitchNode, "switch")                                                      \
   V(CaseNode, "case")                                                          \
   V(WhileNode, "while")                                                        \
   V(DoWhileNode, "dowhile")                                                    \
   V(ForNode, "for")                                                            \
   V(JumpNode, "jump")                                                          \
@@ skipping 532 matching lines @@
   const Token::Kind kind_;
   AstNode* left_;
   AstNode* right_;
 
   bool IsKindValid() const;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(BinaryOpNode);
 };
 
 
-class StringConcatNode : public AstNode {
- public:
-  explicit StringConcatNode(intptr_t token_pos)
-      : AstNode(token_pos),
-        values_(new ArrayNode(token_pos, TypeArguments::ZoneHandle())) {
-  }
-
-  ArrayNode* values() const { return values_; }
-
-  virtual const Instance* EvalConstExpr() const;
-
-  void AddExpr(AstNode* expr) const {
-    values_->AddElement(expr);
-  }
-
-  virtual void VisitChildren(AstNodeVisitor* visitor) const {
-    values_->Visit(visitor);
-  }
-
-  DECLARE_COMMON_NODE_FUNCTIONS(StringConcatNode);
-
- private:
-  ArrayNode* values_;
-  DISALLOW_IMPLICIT_CONSTRUCTORS(StringConcatNode);
-};
-
-
 class UnaryOpNode : public AstNode {
  public:
   // Returns optimized version, e.g., for ('-' '1') ('-1') literal is returned.
   static AstNode* UnaryOpOrLiteral(intptr_t token_pos,
                                    Token::Kind kind,
                                    AstNode* operand);
   UnaryOpNode(intptr_t token_pos,
               Token::Kind kind,
               AstNode* operand)
       : AstNode(token_pos), kind_(kind), operand_(operand) {
@@ skipping 1067 matching lines @@
   const LocalVariable& context_var_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_