Reify type params on map literals

test/codegen_expected/language/ct_const2_test.js

 dart_library.library('language/ct_const2_test', null, /* Imports */[
   'dart_sdk'
 ], function load__ct_const2_test(exports, dart_sdk) {
   'use strict';
   const core = dart_sdk.core;
   const dart = dart_sdk.dart;
   const dartx = dart_sdk.dartx;
   const ct_const2_test = Object.create(null);
   let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
   ct_const2_test.b = true;
   ct_const2_test.s = "apple";
   ct_const2_test.i = 1;
   ct_const2_test.d = 3.3;
   ct_const2_test.h = 15;
   ct_const2_test.n = null;
   ct_const2_test.aList = dart.constList([1, 2, 3], core.int);
-  ct_const2_test.aMap = dart.const(dart.map({"1": "one", "2": "banana"}));
+  ct_const2_test.aMap = dart.const(dart.map({"1": "one", "2": "banana"}, core.String, core.String));
   ct_const2_test.INT_LIT = 5;
   ct_const2_test.INT_LIT_REF = ct_const2_test.INT_LIT;
   ct_const2_test.DOUBLE_LIT = 1.5;
   ct_const2_test.BOOL_LIT = true;
   ct_const2_test.STRING_LIT = "Hello";
   ct_const2_test.BOP1_0 = ct_const2_test.INT_LIT + 1;
   ct_const2_test.BOP1_1 = 1 + ct_const2_test.INT_LIT;
   ct_const2_test.BOP1_2 = ct_const2_test.INT_LIT - 1;
   ct_const2_test.BOP1_3 = 1 - ct_const2_test.INT_LIT;
   ct_const2_test.BOP1_4 = ct_const2_test.INT_LIT * 1;
@@ skipping 71 matching lines @@
     get a() {
       return dart.const(new ct_const2_test.A());
     }
   });
   ct_const2_test.main = function() {
   };
   dart.fn(ct_const2_test.main, VoidTodynamic());
   // Exports:
   exports.ct_const2_test = ct_const2_test;
 });