bsdi-elf needs to link with -ldl.

Configure

@@ -322,7 +322,7 @@ my %table=(
 "FreeBSD-elf",  "gcc:-DTERMIOS -DL_ENDIAN -fomit-frame-pointer -O3 -m486 -Wall::-pthread -D_REENTRANT -D_THREAD_SAFE -D_THREADSAFE:::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_elf_asm}:dlfcn:bsd-gcc-shared:-fPIC:.so.\$(SHLIB_MAJOR).\$(SHLIB_MINOR)",
 "FreeBSD",      "gcc:-DTERMIOS -DL_ENDIAN -fomit-frame-pointer -O3 -m486 -Wall::(unknown):::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_out_asm}",
 "bsdi-gcc",     "gcc:-O3 -ffast-math -DL_ENDIAN -DPERL5 -m486::(unknown):::RSA_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_bsdi_asm}",
-"bsdi-elf-gcc",     "gcc:-DPERL5 -DL_ENDIAN -fomit-frame-pointer -O3 -m486 -Wall::(unknown):::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_elf_asm}:dlfcn:bsd-gcc-shared:-fPIC:.so.\$(SHLIB_MAJOR).\$(SHLIB_MINOR)",
+"bsdi-elf-gcc",     "gcc:-DPERL5 -DL_ENDIAN -fomit-frame-pointer -O3 -m486 -Wall::(unknown)::-ldl:BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_elf_asm}:dlfcn:bsd-gcc-shared:-fPIC:.so.\$(SHLIB_MAJOR).\$(SHLIB_MINOR)",
 "nextstep",	"cc:-O -Wall:<libc.h>:(unknown):::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:::",
 "nextstep3.3",	"cc:-O3 -Wall:<libc.h>:(unknown):::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:::",