Move indexSet and unary operators to the new interceptor mechanism.

sdk/lib/_internal/compiler/implementation/constant_system_dart.dart

 // 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.
 
 part of dart2js;
 
 const DART_CONSTANT_SYSTEM = const DartConstantSystem();
 
 class BitNotOperation implements UnaryOperation {
   final SourceString name = const SourceString('~');
@@ skipping 317 matching lines @@
   }
   apply(left, right) => identical(left, right);
 }
 
 /**
  * A constant system implementing the Dart semantics. This system relies on
  * the underlying runtime-system. That is, if dart2js is run in an environment
  * that doesn't correctly implement Dart's semantics this constant system will
  * not return the correct values.
  */
-class DartConstantSystem implements ConstantSystem {
+class DartConstantSystem extends ConstantSystem {
   const add = const AddOperation();
   const bitAnd = const BitAndOperation();
   const bitNot = const BitNotOperation();
   const bitOr = const BitOrOperation();
   const bitXor = const BitXorOperation();
   const booleanAnd = const BooleanAndOperation();
   const booleanOr = const BooleanOrOperation();
   const divide = const DivideOperation();
   const equal = const EqualsOperation();
   const greaterEqual = const GreaterEqualOperation();
@@ skipping 22 matching lines @@
   bool isInt(Constant constant) => constant.isInt();
   bool isDouble(Constant constant) => constant.isDouble();
   bool isString(Constant constant) => constant.isString();
   bool isBool(Constant constant) => constant.isBool();
   bool isNull(Constant constant) => constant.isNull();
 
   bool isSubtype(Compiler compiler, DartType s, DartType t) {
     return compiler.types.isSubtype(s, t);
   }
 }