[Bug c++/98316] New: [11 regression] cc1plus doesn't link on Solaris 11.3

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98316

            Bug ID: 98316
           Summary: [11 regression] cc1plus doesn't link on Solaris 11.3
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: nathan at gcc dot gnu.org
  Target Milestone: ---
            Target: *-*-solaris2.11

Even with PR c++/98315 hacked around, Solaris 11.3 (only) bootstrap is still
broken:

Undefined                       first referenced
 symbol                             in file
__xnet_connect                      ../libcody/libcody.a(netclient.o)
__xnet_socket                       ../libcody/libcody.a(netclient.o)
__xnet_getaddrinfo                  ../libcody/libcody.a(netclient.o)
freeaddrinfo                        ../libcody/libcody.a(netclient.o)
gai_strerror                        ../libcody/libcody.a(netclient.o)
ld: fatal: symbol referencing errors
collect2: error: ld returned 1 exit status
make[3]: *** [/vol/gcc/src/hg/master/local/gcc/cp/Make-lang.in:136: cc1plus]
Error 1

Before Solaris 11.4 folded libsocket and libnsl into libc, one needed to link
with both for the socket functions.  The same issue exists with the other use
of $(LIBCODY) in c++tools/Makefile.in.

We already have 4 instances of the libsocket/libnsl check in the tree:

  gotools/configure.ac
  libcc1/configure.ac
  libgo/configure.ac
  libphobos/m4/druntime/libraries.m4

Instead of adding yet two others, we could make use of the autoconf-archive's
m4/ax_lib_socket_nsl.m4 (AX_LIB_SOCKET_NSL).