fixes #415, correct type for map literals

lib/runtime/dart/_operations.js

Index: lib/runtime/dart/_operations.js
diff --git a/lib/runtime/dart/_operations.js b/lib/runtime/dart/_operations.js
index 3af72e9ae3a7ee17e4a87b1c54fe01ef70b6bc28..de193c2ba5c58cb411737b58861f5212eb5a8ed1 100644
--- a/lib/runtime/dart/_operations.js
+++ b/lib/runtime/dart/_operations.js
@@ -278,8 +278,10 @@ dart_library.library('dart/_operations', null, /* Imports */[
    * example `map()`.
    */
   // TODO(jmesserly): this could be faster
-  function map(values) {
-    let map = collection.LinkedHashMap.new();
+  function map(values, K, V) {

[vsm, 2016/01/20 23:39:33]

FWIW, dart.list is in _classes.  Kind of strange that these ended up in
different places.

[Jennifer Messerly, 2016/02/01 23:39:48]

Nice find. Added TODO.

+    if (K === void 0) K = types.dynamic;
+    if (V === void 0) V = types.dynamic;
+    let map = collection.LinkedHashMap$(K, V).new();
     if (Array.isArray(values)) {
       for (let i = 0, end = values.length - 1; i < end; i += 2) {
         let key = values[i];