Infer types for compile-time constant closures.

tests/compiler/dart2js/simple_inferrer_const_closure4_test.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2014, 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.
 
-// Test that we are analyzing field parameters correctly.
-
 import 'package:expect/expect.dart';
 import "package:async_helper/async_helper.dart";
 import 'compiler_helper.dart';
-import 'parser_helper.dart';
 
 const String TEST = """
 
-class A {
-  final dynamicField;
-  A() : dynamicField = 42;
-  A.bar(this.dynamicField);
+method(a) {  // Called via [foo] with integer then double.
+  return a;
+}
+
+const foo = method;
+
+returnNum(x) {
+  return foo(x);
 }
 
 main() {
-  new A();
-  new A.bar('foo');
+  returnNum(10);
+  returnNum(10.5);
 }
 """;
 
+
 void main() {
   Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(TEST, uri);
   asyncTest(() => compiler.runCompiler(uri).then((_) {
     var typesInferrer = compiler.typesTask.typesInferrer;
 
-    checkFieldTypeInClass(String className, String fieldName, type) {
-      var cls = findElement(compiler, className);
-      var element = cls.lookupLocalMember(fieldName);
+    checkArgument(String functionName, type) {
+      var functionElement = findElement(compiler, functionName);
+      var signature = functionElement.functionSignature;
+      var element = signature.requiredParameters.first;
       Expect.equals(type,
-          typesInferrer.getTypeOfElement(element).simplify(compiler));
+          typesInferrer.getTypeOfElement(element).simplify(compiler),
+          functionName);
     }
 
-    checkFieldTypeInClass('A', 'dynamicField',
-        findTypeMask(compiler, 'Interceptor', 'nonNullSubclass'));
+    checkArgument('method', compiler.typesTask.numType);
+    checkArgument('returnNum', compiler.typesTask.numType);
   }));
 }