On Solaris, catch code for C++ exceptions is in libgcc_s.  The libc has
default catch code as well, that does an abort.  GCC by default emits on
purpose -lgcc_s -lc -lgcc_s.  libtool's de-duplication magic turns this
into -lc -lgcc_s, which unsurprisingly is the wrong order, since
exceptions will be seen by libc first.  Disable de-duplication for this
reason, such that we can have working C++ libtool built libraries.

--- libltdl/config/ltmain.m4sh
+++ libltdl/config/ltmain.m4sh
@@ -398,7 +398,7 @@
   test "$opt_debug" = : || func_append preserve_args " --debug"
 
   case $host in
-    *cygwin* | *mingw* | *pw32* | *cegcc*)
+    *cygwin* | *mingw* | *pw32* | *cegcc* | *solaris2*)
       # don't eliminate duplications in $postdeps and $predeps
       opt_duplicate_compiler_generated_deps=:
       ;;
--- libltdl/config/ltmain.sh
+++ libltdl/config/ltmain.sh
@@ -1180,7 +1180,7 @@
   test "$opt_debug" = : || func_append preserve_args " --debug"
 
   case $host in
-    *cygwin* | *mingw* | *pw32* | *cegcc*)
+    *cygwin* | *mingw* | *pw32* | *cegcc* | *solaris2*)
       # don't eliminate duplications in $postdeps and $predeps
       opt_duplicate_compiler_generated_deps=:
       ;;