Update links to archived copy of SGI STL docs
* doc/xml/faq.xml: Update links to archived copy of SGI STL docs.
* doc/xml/manual/backwards_compatibility.xml: Likewise.
* doc/xml/manual/containers.xml: Likewise.
* doc/xml/manual/debug_mode.xml: Likewise.
* doc/xml/manual/extensions.xml: Likewise.
* doc/xml/manual/policy_data_structures_biblio.xml: Likewise.
* doc/xml/manual/using.xml: Likewise.
* doc/xml/manual/utilities.xml: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@259286 138bc75d-0d04-0410-961f-82ee72b054a4