Merge CoreTypes and CoreClasses into CommonElements.

pkg/compiler/lib/src/ssa/kernel_impact.dart

 // Copyright (c) 2016, 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.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
 import '../constants/expressions.dart';
@@ skipping 204 matching lines @@
   void visitNullLiteral(ir.NullLiteral literal) {
     impactBuilder.registerConstantLiteral(new NullConstantExpression());
   }
 
   @override
   void visitListLiteral(ir.ListLiteral literal) {
     visitNodes(literal.expressions);
     DartType elementType = checkType(literal.typeArgument);
 
     impactBuilder.registerListLiteral(new ListLiteralUse(
-        compiler.coreTypes.listType(elementType),
+        compiler.commonElements.listType(elementType),
         isConstant: literal.isConst,
         isEmpty: literal.expressions.isEmpty));
   }
 
   @override
   void visitMapLiteral(ir.MapLiteral literal) {
     visitNodes(literal.entries);
     DartType keyType = checkType(literal.keyType);
     DartType valueType = checkType(literal.valueType);
     impactBuilder.registerMapLiteral(new MapLiteralUse(
-        compiler.coreTypes.mapType(keyType, valueType),
+        compiler.commonElements.mapType(keyType, valueType),
         isConstant: literal.isConst,
         isEmpty: literal.entries.isEmpty));
   }
 
   void visitMapEntry(ir.MapEntry entry) {
     visitNode(entry.key);
     visitNode(entry.value);
   }
 
   void _visitArguments(ir.Arguments arguments) {
@@ skipping 320 matching lines @@
     Element target = astAdapter.getElement(node.target).declaration;
     impactBuilder.registerStaticUse(new StaticUse.superConstructorInvoke(
         target, astAdapter.getCallStructure(node.arguments)));
   }
 
   // TODO(johnniwinther): Make this throw and visit child nodes explicitly
   // instead to ensure that we don't visit unwanted parts of the ir.
   @override
   void defaultNode(ir.Node node) => node.visitChildren(this);
 }