Avoid using Function.prototype.call in a number of places in our

src/regexp.js

Index: src/regexp.js
diff --git a/src/regexp.js b/src/regexp.js
index 0de66c644ed4fcfcd94d4826d700e24b7a6f7976..5b7e3a9d2f80563889c95d9b04b8306c4bb7936d 100644
--- a/src/regexp.js
+++ b/src/regexp.js
@@ -52,7 +52,7 @@ function DoConstructRegExp(object, pattern, flags) {
   var multiline = false;
 
   for (var i = 0; i < flags.length; i++) {
-    var c = StringCharAt.call(flags, i);
+    var c = %_CallFunction(flags, i, StringCharAt);
     switch (c) {
       case 'g':
         // Allow duplicate flags to be consistent with JSC and others.