Fix bug in JSON character quote table.

Review URL: http://codereview.chromium.org/3349006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5399 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/json.js

@@ -74,7 +74,7 @@ var characterQuoteCache = {
   '\f': '\\f',  // ASCII 12, Formfeed
   '\r': '\\r',  // ASCII 13, Carriage Return
   '\"': '\\"',
-  '/': '\\/'
+  '\\': '\\\\'
 };
 
 function QuoteSingleJSONCharacter(c) {