Call builtin code wrapped in functions from the bootstrapper.

src/string.js

Index: src/string.js
diff --git a/src/string.js b/src/string.js
index a9cf8669fbd723022de5cc6a6217391c9709d8a6..03979fded3fe61a481568f4538ed93a930381c70 100644
--- a/src/string.js
+++ b/src/string.js
@@ -6,7 +6,7 @@ var $stringCharAt;
 var $stringIndexOf;
 var $stringSubstring;
 
-(function() {
+(function(global, shared, exports) {
 
 %CheckIsBootstrapping();
 
@@ -1171,4 +1171,4 @@ $stringCharAt = StringCharAtJS;
 $stringIndexOf = StringIndexOfJS;
 $stringSubstring = StringSubstring;
 
-})();
+})