Reify type params on map literals

test/codegen_expected/language/closure_in_field_initializer_test.js

 dart_library.library('language/closure_in_field_initializer_test', null, /* Imports */[
   'dart_sdk',
   'expect'
 ], function load__closure_in_field_initializer_test(exports, dart_sdk, expect) {
   'use strict';
   const core = dart_sdk.core;
   const dart = dart_sdk.dart;
   const dartx = dart_sdk.dartx;
   const expect$ = expect.expect;
   const closure_in_field_initializer_test = Object.create(null);
-  let dynamicAnddynamicTodynamic = () => (dynamicAnddynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic, dart.dynamic])))();
+  let dynamicAnddynamicTodynamic = () => (dynamicAnddynamicTodynamic = dart.constFn(dart.functionType(dart.dynamic, [dart.dynamic, dart.dynamic])))();
+  let dynamicAnddynamicTodynamic$ = () => (dynamicAnddynamicTodynamic$ = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic, dart.dynamic])))();
   let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
   closure_in_field_initializer_test.Foo = class Foo extends core.Object {
     new() {
-      this.closures = dart.map({a: dart.fn((x, y) => dart.dsend(x, '+', y), dynamicAnddynamicTodynamic())});
+      this.closures = dart.map({a: dart.fn((x, y) => dart.dsend(x, '+', y), dynamicAnddynamicTodynamic$())}, core.String, dynamicAnddynamicTodynamic());
     }
   };
   closure_in_field_initializer_test.main = function() {
     let closures = new closure_in_field_initializer_test.Foo().closures;
     expect$.Expect.equals(6, dart.dcall(closures[dartx.get]('a'), 4, 2));
   };
   dart.fn(closure_in_field_initializer_test.main, VoidTodynamic());
   // Exports:
   exports.closure_in_field_initializer_test = closure_in_field_initializer_test;
 });