dart2js cps: Make Identical a built-in and add Interceptor to Tree IR.

pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart

 // Copyright (c) 2014, 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.
 
 library tree_ir_nodes;
 
 import '../constants/expressions.dart';
 import '../constants/values.dart' as values;
 import '../dart_types.dart' show DartType, InterfaceType, TypeVariableType;
 import '../elements/elements.dart';
@@ skipping 750 matching lines @@
 
   accept(ExpressionVisitor visitor) {
     return visitor.visitCreateInvocationMirror(this);
   }
 
   accept1(ExpressionVisitor1 visitor, arg) {
     return visitor.visitCreateInvocationMirror(this, arg);
   }
 }
 
+class Interceptor extends Expression {
+  Expression input;
+  Set<ClassElement> interceptedClasses;
+
+  Interceptor(this.input, this.interceptedClasses);
+
+  accept(ExpressionVisitor visitor) {
+    return visitor.visitInterceptor(this);
+  }
+
+  accept1(ExpressionVisitor1 visitor, arg) {
+    return visitor.visitInterceptor(this, arg);
+  }
+}
+
 class ForeignCode extends Node {
   final js.Template codeTemplate;
   final types.TypeMask type;
   final List<Expression> arguments;
   final native.NativeBehavior nativeBehavior;
   final Element dependency;
 
   ForeignCode(this.codeTemplate, this.type, this.arguments, this.nativeBehavior,
       this.dependency);
 }
@@ skipping 74 matching lines @@
   E visitGetField(GetField node);
   E visitSetField(SetField node);
   E visitGetStatic(GetStatic node);
   E visitSetStatic(SetStatic node);
   E visitCreateBox(CreateBox node);
   E visitCreateInstance(CreateInstance node);
   E visitReifyRuntimeType(ReifyRuntimeType node);
   E visitReadTypeVariable(ReadTypeVariable node);
   E visitTypeExpression(TypeExpression node);
   E visitCreateInvocationMirror(CreateInvocationMirror node);
+  E visitInterceptor(Interceptor node);
   E visitApplyBuiltinOperator(ApplyBuiltinOperator node);
   E visitForeignExpression(ForeignExpression node);
 }
 
 abstract class ExpressionVisitor1<E, A> {
   E visitExpression(Expression node, A arg) => node.accept1(this, arg);
   E visitVariableUse(VariableUse node, A arg);
   E visitAssign(Assign node, A arg);
   E visitInvokeStatic(InvokeStatic node, A arg);
   E visitInvokeMethod(InvokeMethod node, A arg);
@@ skipping 11 matching lines @@
   E visitGetField(GetField node, A arg);
   E visitSetField(SetField node, A arg);
   E visitGetStatic(GetStatic node, A arg);
   E visitSetStatic(SetStatic node, A arg);
   E visitCreateBox(CreateBox node, A arg);
   E visitCreateInstance(CreateInstance node, A arg);
   E visitReifyRuntimeType(ReifyRuntimeType node, A arg);
   E visitReadTypeVariable(ReadTypeVariable node, A arg);
   E visitTypeExpression(TypeExpression node, A arg);
   E visitCreateInvocationMirror(CreateInvocationMirror node, A arg);
+  E visitInterceptor(Interceptor node, A arg);
   E visitApplyBuiltinOperator(ApplyBuiltinOperator node, A arg);
   E visitForeignExpression(ForeignExpression node, A arg);
 }
 
 abstract class StatementVisitor<S> {
   S visitStatement(Statement node) => node.accept(this);
   S visitLabeledStatement(LabeledStatement node);
   S visitReturn(Return node);
   S visitThrow(Throw node);
   S visitRethrow(Rethrow node);
@@ skipping 184 matching lines @@
     node.arguments.forEach(visitExpression);
   }
 
   visitUnreachable(Unreachable node) {
   }
 
   visitApplyBuiltinOperator(ApplyBuiltinOperator node) {
     node.arguments.forEach(visitExpression);
   }
 
+  visitInterceptor(Interceptor node) {
+    visitExpression(node.input);
+  }
+
   visitForeignCode(ForeignCode node) {
     node.arguments.forEach(visitExpression);
   }
 
   visitForeignExpression(ForeignExpression node) => visitForeignCode(node);
   visitForeignStatement(ForeignStatement node) => visitForeignCode(node);
 }
 
 abstract class Transformer implements ExpressionVisitor<Expression>,
                                       StatementVisitor<Statement> {
@@ skipping 196 matching lines @@
   }
 
   visitUnreachable(Unreachable node) {
     return node;
   }
 
   visitApplyBuiltinOperator(ApplyBuiltinOperator node) {
     _replaceExpressions(node.arguments);
     return node;
   }
+
+  visitInterceptor(Interceptor node) {
+    node.input = visitExpression(node.input);
+    return node;
+  }
 }