Recursion limit for one-char string replace and retire String::kMinNonFlatLength.

src/string.js

Index: src/string.js
diff --git a/src/string.js b/src/string.js
index e858b0fd526e7c8b8995981460bf7130b5974228..2d6896120e5c7c2633fd550a085b1624eb62ada6 100644
--- a/src/string.js
+++ b/src/string.js
@@ -245,8 +245,12 @@ function StringReplace(search, replace) {
   // Convert the search argument to a string and search for it.
   search = TO_STRING_INLINE(search);
   if (search.length == 1 &&
+      subject.length > 0xFF &&

[Yang, 2012/01/17 13:07:34]

Dealing with short cons string the old way is better than traversing it.  This
especially makes celtic kane happy.

       IS_STRING(replace) &&
       %StringIndexOf(replace, '$', 0) < 0) {
+    // Searching by traversing a cons string tree and replace with cons of
+    // slices works only when the replaced string is a single character, being
+    // replaced by a simple string and only pays off for long strings.
     return %StringReplaceOneCharWithString(subject, search, replace);
   }
   var start = %StringIndexOf(subject, search, 0);