Call JS functions via native context instead of js builtins object.

src/date.js

Index: src/date.js
diff --git a/src/date.js b/src/date.js
index 3d0693a56f15d4a1c73b0ceb5a11d7aa22b2be6d..2be8bcb220a7f3ed91ea1fb6943fa79398d5e4a7 100644
--- a/src/date.js
+++ b/src/date.js
@@ -883,8 +883,6 @@ utils.InstallFunctions(GlobalDate.prototype, DONT_ENUM, [
   "toJSON", DateToJSON
 ]);
 
-utils.ExportToRuntime(function(to) {
-  to["create_date_fun"] = CreateDate;
-});
+%InstallToContext(["create_date_fun", CreateDate]);
 
 })