libstdc++: Fix incorrect links to archived SGI STL docs

libstdc++: Fix incorrect links to archived SGI STL docs

In r8-7777-g25949ee33201f2 I updated some URLs to point to copies of the
SGI STL docs in the Wayback Machine, because the original pags were no
longer hosted on sgi.com. However, I incorrectly assumed that if one
archived page was at https://web.archive.org/web/20171225062613/... then
all the other pages would be too. Apparently that's not how the Wayback
Machine works, and each page is archived on a different date. That meant
that some of our links were redirecting to archived copies of the
announcement that the SGI STL docs have gone away.

This fixes each URL to refer to a correctly archived copy of the
original docs.

libstdc++-v3/ChangeLog:

	* doc/xml/faq.xml: Update URL for archived SGI STL docs.
	* doc/xml/manual/containers.xml: Likewise.
	* doc/xml/manual/extensions.xml: Likewise.
	* doc/xml/manual/using.xml: Likewise.
	* doc/xml/manual/utilities.xml: Likewise.
	* doc/html/*: Regenerate.

(cherry picked from commit 501e6e786652748ff0ad9a322f74b9b47970031f)