fixes for angular hello: String + and disable broken arg parsing

test/codegen/expect/fieldtest.js

Index: test/codegen/expect/fieldtest.js
diff --git a/test/codegen/expect/fieldtest.js b/test/codegen/expect/fieldtest.js
index 81d970e72071a52f2fad295381fcb2908d238f03..9354cf6742d7c7fd365d7343aeb536e991928128 100644
--- a/test/codegen/expect/fieldtest.js
+++ b/test/codegen/expect/fieldtest.js
@@ -43,7 +43,7 @@ var fieldtest;
   });
   dart.copyProperties(exports, {
     get q() {
-      return core.String['+'](core.String['+']('life, ', 'the universe '), 'and everything');
+      return 'life, ' + 'the universe ' + 'and everything';
     },
     get z() {
       return 42;