Handle more constants in Constantifier

tests/compiler/dart2js/constant_expression_evaluate_test.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 dart2js.constants.expressions.evaluate_test;
 
 import 'dart:async';
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 import 'package:compiler/src/common/backend_api.dart';
@@ skipping 21 matching lines @@
 class ConstantData {
   /// Source code for the constant expression.
   final String code;
 
   /// Map from environment to expected constant value as structured text.
   final Map<Map<String, String>, String> expectedValues;
 
   const ConstantData(this.code, this.expectedValues);
 }
 
-class MemoryEnvironment implements Environment {
+class MemoryEnvironment implements EvaluationEnvironment {
   final Compiler _compiler;
   final Map<String, String> env;
 
   MemoryEnvironment(this._compiler, [this.env = const <String, String>{}]);
 
   @override
   String readFromEnvironment(String name) => env[name];
 
   @override
   ResolutionInterfaceType substByContext(
@@ skipping 221 matching lines @@
   sb.write('main() {}\n');
   String source = sb.toString();
   CompilationResult result = await runCompiler(
       memorySourceFiles: {'main.dart': source}, options: ['--analyze-all']);
   Compiler compiler = result.compiler;
   var library = compiler.mainApp;
   constants.forEach((String name, ConstantData data) {
     FieldElement field = library.localLookup(name);
     ConstantExpression constant = field.constant;
     data.expectedValues.forEach((Map<String, String> env, String expectedText) {
-      Environment environment = new MemoryEnvironment(compiler, env);
+      EvaluationEnvironment environment = new MemoryEnvironment(compiler, env);
       ConstantValue value =
           constant.evaluate(environment, DART_CONSTANT_SYSTEM);
       String valueText = value.toStructuredText();
       Expect.equals(
           expectedText,
           valueText,
           "Unexpected value '${valueText}' for constant "
           "`${constant.toDartText()}`, expected '${expectedText}'.");
     });
   });
 }