Introduce InternalPackedArray.

src/string.js

Index: src/string.js
diff --git a/src/string.js b/src/string.js
index b39976c51ed8a15332eccabecc2d1c34e26cf962..2f7df7078e7bf25733d1f924fbbea4a319e6e772 100644
--- a/src/string.js
+++ b/src/string.js
@@ -420,7 +420,7 @@ function StringReplaceGlobalRegExpWithFunction(subject, regexp, replace) {
     // input string and some replacements that were returned from the replace
     // function.
     var match_start = 0;
-    var override = new InternalArray(null, 0, subject);
+    var override = new InternalPackedArray(null, 0, subject);
     var receiver = %GetDefaultReceiver(replace);
     for (var i = 0; i < len; i++) {
       var elem = res[i];
@@ -821,8 +821,6 @@ function StringTrimRight() {
   return %StringTrim(TO_STRING_INLINE(this), false, true);
 }
 
-var static_charcode_array = new InternalArray(4);
-
 
 // ECMA-262, section 15.5.3.2
 function StringFromCharCode(code) {