Fixed string.split: always convert non-regexp separator to string.

src/string.js

Index: src/string.js
diff --git a/src/string.js b/src/string.js
index 297105d0474fa73d1653f9ffbc582b49c45a6624..9bc8e850364d96469d66dd4d0c195ac2b891dc6d 100644
--- a/src/string.js
+++ b/src/string.js
@@ -568,7 +568,6 @@ function StringSplit(separator, limit) {
   }
   var subject = TO_STRING_INLINE(this);
   limit = (IS_UNDEFINED(limit)) ? 0xffffffff : TO_UINT32(limit);
-  if (limit === 0) return [];
 
   // ECMA-262 says that if separator is undefined, the result should
   // be an array of size 1 containing the entire string.  SpiderMonkey
@@ -582,6 +581,9 @@ function StringSplit(separator, limit) {
   var length = subject.length;
   if (!IS_REGEXP(separator)) {
     separator = TO_STRING_INLINE(separator);
+    
+    if (limit === 0) return [];
+    
     var separator_length = separator.length;
 
     // If the separator string is empty then return the elements in the subject.
@@ -591,6 +593,8 @@ function StringSplit(separator, limit) {
 
     return result;
   }
+  
+  if (limit === 0) return [];
 
   %_Log('regexp', 'regexp-split,%0S,%1r', [subject, separator]);