Introduce fast native caches and use it in String.search.

src/string.js

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 511 matching lines @@
   }
   var parameters = $Array(m + 2);
   for (var j = 0; j < m; j++) {
     parameters[j] = CaptureString(subject, matchInfo, j);
   }
   parameters[j] = index;
   parameters[j + 1] = subject;
   return replace.apply(null, parameters);
 }
 
-
 // ECMA-262 section 15.5.4.12
 function StringSearch(re) {
-  var regexp = new $RegExp(re);
+  var regexp;
+  if (IS_STRING(re)) {
+    regexp = %_GetFromCache(STRING_TO_REGEXP_CACHE_ID, re);
+  } else if (IS_REGEXP(re)) {
+    regexp = re;
+  } else {
+    regexp = new $RegExp(re);
+  }
   var s = TO_STRING_INLINE(this);
   var match = DoRegExpExec(regexp, s, 0);
   if (match) {
     lastMatchInfo = match;
     return match[CAPTURE0];
   }
   return -1;
 }
 
 
@@ skipping 452 matching lines @@
     "small", StringSmall,
     "strike", StringStrike,
     "sub", StringSub,
     "sup", StringSup,
     "toJSON", StringToJSON
   ));
 }
 
 
 SetupString();