Store constant variable initializers in elements.

pkg/compiler/lib/src/cps_ir/inline.dart

 // Copyright (c) 2015, 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 cps_ir.optimization.inline;
 
 import 'package:js_ast/js_ast.dart' as js;
 
 import '../dart_types.dart' show DartType, GenericType;
 import '../elements/elements.dart';
@@ skipping 359 matching lines @@
           node.selector.callStructure.getOrderedNamedArguments();
       List<String> outgoingNames = <String>[];
       int nameIndex = 0;
       signature.orderedOptionalParameters.forEach((ParameterElement formal) {
         if (nameIndex < incomingNames.length &&
             formal.name == incomingNames[nameIndex]) {
           arguments.add(parameters[parameterIndex++]);
           ++nameIndex;
         } else {
           Constant defaultValue = cps.makeConstant(
-              backend.constants.getConstantValueForVariable(formal));
+              backend.constants.getConstantValue(formal.constant));
           defaultValue.type = typeSystem.getParameterType(formal);
           arguments.add(defaultValue);
         }
         outgoingNames.add(formal.name);
       });
       newCallStructure =
           new CallStructure(signature.parameterCount, outgoingNames);
     } else {
       signature.forEachOptionalParameter((ParameterElement formal) {
         if (parameterIndex < parameters.length) {
           arguments.add(parameters[parameterIndex++]);
         } else {
           Constant defaultValue = cps.makeConstant(
-              backend.constants.getConstantValueForVariable(formal));
+              backend.constants.getConstantValue(formal.constant));
           defaultValue.type = typeSystem.getParameterType(formal);
           arguments.add(defaultValue);
         }
       });
       newCallStructure = new CallStructure(signature.parameterCount);
     }
 
     Selector newSelector = new Selector(
         node.selector.kind, node.selector.memberName, newCallStructure);
     Primitive result = cps.invokeMethod(
@@ skipping 199 matching lines @@
         (enclosingClass == backend.helpers.jsNumberClass ||
             enclosingClass == backend.helpers.jsDoubleClass ||
             enclosingClass == backend.helpers.jsIntClass)) {
       // These should be handled by operator specialization.
       return true;
     }
     if (target == backend.helpers.stringInterpolationHelper) return true;
     return false;
   }
 }