and String::WriteAscii and add test.  Correct implementation of
String::Write, fixing bug 975 (the patch in that bug was not
used, however).
Review URL: http://codereview.chromium.org/5718005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6011 ce2b1a6d-e550-0410-aec6-3dcde31c8c00