This fixes missing libiconv symbols when libstdc++ is built on a system
that has libiconv installed. If the libiconv headers are found then
libstdc++ depends on libiconv_open etc instead of libc's iconv_open. But
without this fix libstdc++ is not linked to the libiconv library that
provides the definitions of those symbols.
As discussed in PR 93602 this changed means that libstdc++.so.6 might
have an rpath pointing to the location of the libiconv.so library. If
that is not desired, then GCC must be configured to link to a static
libiconv.a instead, using either --with-libiconv-type=static or an
in-tree build of libiconv.
libstdc++-v3/ChangeLog:
PR libstdc++/93602
* doc/xml/manual/prerequisites.xml: Document libiconv
workarounds.
* doc/html/manual/setup.html: Regenerate.
* src/Makefile.am (CXXLINK): Add $(LTLIBICONV).
* src/Makefile.in: Regenerate.
