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

tests/compiler/dart2js/least_upper_bound_test.dart

Index: tests/compiler/dart2js/least_upper_bound_test.dart
diff --git a/tests/compiler/dart2js/least_upper_bound_test.dart b/tests/compiler/dart2js/least_upper_bound_test.dart
index d239812d26865ca62dc1a75c96ce7e8c85dbf6f6..9d7af4d23e13ab56e8632c52b500d96ab1fdd456 100644
--- a/tests/compiler/dart2js/least_upper_bound_test.dart
+++ b/tests/compiler/dart2js/least_upper_bound_test.dart
@@ -381,12 +381,12 @@ void testFunction() {
     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}');
     }