You do not re-install Safari.
You can restore your iphone.
Page 200 of the manual:
" If you restore, the latest version of iPhone software is reinstalled, default settings are
restored, and data stored on iPhone is deleted, including downloaded applications,
songs, videos, contacts, photos, calendar information, and any other data. In iTunes,
you can also restore from a backup without deleting data stored on iPhone.
"
http://manuals.info.apple.com/enUS/iPhone_UserGuide.pdf