Add a TypeInformation abstraction in the inferrer, that holds information per element, to get rid o…

tests/compiler/dart2js/simple_inferrer_no_such_method_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.
 
 import 'package:expect/expect.dart';
 
 import 'compiler_helper.dart';
 import 'parser_helper.dart';
 
 const String TEST1 = """
@@ skipping 85 matching lines @@
   Uri uri = new Uri(scheme: 'source');
 
   var compiler = compilerFor(TEST1, uri);
   compiler.runCompiler(uri);
   var typesInferrer = compiler.typesTask.typesInferrer;
 
   checkReturn(String name, type) {
     var element = findElement(compiler, name);
     Expect.equals(
         type,
-        typesInferrer.internal.returnTypeOf[element].simplify(compiler),
+        typesInferrer.getReturnTypeOfElement(element).simplify(compiler),
         name);
   }
 
   checkReturn('test1', typesInferrer.intType);
   checkReturn('test2', typesInferrer.dynamicType.nonNullable());
   checkReturn('test3', typesInferrer.intType);
   checkReturn('test4', typesInferrer.mapType);
   checkReturn('test5', typesInferrer.dynamicType.nonNullable());
   checkReturn('test6', typesInferrer.dynamicType.nonNullable());
 
   compiler = compilerFor(TEST2, uri);
   compiler.runCompiler(uri);
   typesInferrer = compiler.typesTask.typesInferrer;
 
   checkReturn('test1', typesInferrer.dynamicType.nonNullable());
   checkReturn('test2', typesInferrer.mapType);
   checkReturn('test3', typesInferrer.mapType);
   checkReturn('test4', typesInferrer.mapType);
   checkReturn('test5', typesInferrer.mapType);
 
   checkReturn('test6', typesInferrer.numType);
   checkReturn('test7', typesInferrer.intType);
   checkReturn('test8', typesInferrer.intType);
   checkReturn('test9', typesInferrer.intType);
   checkReturn('test10', typesInferrer.numType);
   checkReturn('test11', typesInferrer.doubleType);
 }