Enable downward inference on default params

test/checker/inferred_type_test.dart

 // Copyright (c) 2015, 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.
 
 /// Tests for type inference.
 library dev_compiler.test.inferred_type_test;
 
 import 'package:unittest/unittest.dart';
 
 import 'package:dev_compiler/src/testing.dart';
@@ skipping 1324 matching lines @@
       }
         ''';
     testChecker({'/main.dart': mk("info:InferredTypeAllocation")},
         inferDownwards: true);
     testChecker({'/main.dart': mk("severe:StaticTypeError")},
         inferDownwards: false);
   });
 
   test('downwards inference on list literals', () {
     String mk(String info) => '''
+      void foo([List<String> list1 = /*$info*/const [],
+                List<String> list2 = /*severe:StaticTypeError*/const [42]]) {
+      }
+
       void main() {
         {
           List<int> l0 = /*$info*/[];
           List<int> l1 = /*$info*/[3];
           List<int> l2 = /*severe:StaticTypeError*/["hello"];
           List<int> l3 = /*severe:StaticTypeError*/["hello", 3];
         }
         {
           List<dynamic> l0 = [];
           List<dynamic> l1 = [3];
@@ skipping 61 matching lines @@
       }
       ''';
     testChecker({'/main.dart': mk("info:InferredTypeLiteral")},
         inferDownwards: true);
     testChecker({'/main.dart': mk("severe:StaticTypeError")},
         inferDownwards: false);
   });
 
   test('downwards inference on map literals', () {
     String mk(String info) => '''
+      void foo([Map<int, String> m1 = /*$info*/const {1: "hello"},
+                Map<int, String> m1 = /*severe:StaticTypeError*/const {"hello": "world"}]) {
+      }
       void main() {
         {
           Map<int, String> l0 = /*$info*/{};
           Map<int, String> l1 = /*$info*/{3: "hello"};
           Map<int, String> l2 = /*severe:StaticTypeError*/{"hello": "hello"};
           Map<int, String> l3 = /*severe:StaticTypeError*/{3: 3};
           Map<int, String> l4 = /*severe:StaticTypeError*/{3:"hello", "hello": 3};
         }
         {
           Map<dynamic, dynamic> l0 = {};
@@ skipping 67 matching lines @@
           Function2<int, int> l1 = /*info:InferredTypeClosure*/(x) => x+1;
           Function2<int, String> l2 = /*info:InferredTypeClosure should be severe:StaticTypeError*/(x) => x;
           Function2<int, String> l3 = /*info:InferredTypeClosure should be severe:StaticTypeError*/(x) => /*info:DynamicInvoke should be pass*/x.substring(3);
           Function2<String, String> l4 = /*info:InferredTypeClosure*/(x) => /*info:DynamicInvoke should be pass*/x.substring(3);
         }
       }
       '''
     }, inferDownwards: true, wrapClosures: false);
   });
 }