Add Resolution and Parsing interfaces for computeType, ensureResolved and parseNode.

tests/compiler/dart2js/least_upper_bound_test.dart

 // Copyright (c) 2013, 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 subtype_test;
 
 import 'package:expect/expect.dart';
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/dart_types.dart';
 import 'package:compiler/src/elements/elements.dart'
@@ skipping 363 matching lines @@
     FunctionType void__Object_B =
         env.functionType(void_, [Object_, B]);
     FunctionType void__Object_C =
         env.functionType(void_, [Object_, C]);
     FunctionType void__B_Object =
         env.functionType(void_, [B, Object_]);
 
     checkLub(DartType a, DartType b, DartType expectedLub) {
       DartType lub = env.computeLeastUpperBound(a, b);
       if (a != b) {
-        expectedLub = expectedLub.unalias(env.compiler);
-        lub = lub.unalias(env.compiler);
+        expectedLub = expectedLub.unalias(env.compiler.resolution);
+        lub = lub.unalias(env.compiler.resolution);
       }
       Expect.equals(expectedLub, lub,
-          'Unexpected lub(${a.unalias(env.compiler)},'
-                         '${b.unalias(env.compiler)}) = '
+          'Unexpected lub(${a.unalias(env.compiler.resolution)},'
+                         '${b.unalias(env.compiler.resolution)}) = '
                          '${lub}, expected ${expectedLub}');
     }
 
     checkLub(Object_, Object_, Object_);
     checkLub(Object_, Function_, Object_);
     checkLub(Object_, dynamic__, Object_);
     checkLub(Object_, void__, Object_);
     checkLub(Object_, A__, Object_);
     checkLub(Object_, B__, Object_);
     checkLub(Object_, C__, Object_);
@@ skipping 443 matching lines @@
     checkLub(X, S, Object_);
     checkLub(X, T, T);
     checkLub(X, U, B);
     checkLub(X, V, T);
     checkLub(X, W, T);
     checkLub(X, X, X);
   }));
 }