fixes #157, renaming local library identifiers if needed.

test/codegen/expect/misc.js

Index: test/codegen/expect/misc.js
diff --git a/test/codegen/expect/misc.js b/test/codegen/expect/misc.js
index bf0cf8698329eea96fb339a89b2e71106e53391f..a59fd6cb1b4b14a1537ff45ce995470c73859096 100644
--- a/test/codegen/expect/misc.js
+++ b/test/codegen/expect/misc.js
@@ -1,5 +1,6 @@
-var misc;
-(function(exports) {
+var misc = dart.defineLibrary(misc, {});
+var core = dart.import(core);
+(function(exports, core) {
   'use strict';
   // Function main: () → dynamic
   function main() {
@@ -9,4 +10,4 @@ var misc;
   }
   // Exports:
   exports.main = main;
-})(misc || (misc = {}));
+})(misc, core);