Bundled libffi is broken on powerpc: ffi_darwin.c: error: unknown type name 'ffi_go_closure'

ffi_go_closure is not implemented in Darwin-specific files, but declared as extern. However, apparently, nothing provides it. If implementation from aix-closure is compatible, it should be included in the build; if not, then nothing should refer to ffi_go_closure on macOS.

libtool: compile:  /opt/local/bin/gcc-mp-14 -fPIC -fno-common -DHAVE_CONFIG_H -I. -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi -I. -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/include -Iinclude -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/src -isystem/opt/local/include/LegacySupport -I/opt/local/include -pipe -Os -arch ppc64 -fPIC -fno-common -D_THREAD_SAFE -Wall -fexceptions -MT src/closures.lo -MD -MP -MF src/.deps/closures.Tpo -c /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/src/closures.c -o src/closures.o
libtool: compile:  /opt/local/bin/gcc-mp-14 -fPIC -fno-common -DHAVE_CONFIG_H -I. -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi -I. -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/include -Iinclude -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/src -isystem/opt/local/include/LegacySupport -I/opt/local/include -pipe -Os -arch ppc64 -fPIC -fno-common -D_THREAD_SAFE -Wall -fexceptions -MT src/powerpc/ffi_darwin.lo -MD -MP -MF src/powerpc/.deps/ffi_darwin.Tpo -c /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/src/powerpc/ffi_darwin.c -o src/powerpc/ffi_darwin.o
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/src/powerpc/ffi_darwin.c:1114:22: error: unknown type name 'ffi_go_closure'; did you mean 'ffi_raw_closure'?
 1114 | ffi_prep_go_closure (ffi_go_closure* closure,
      |                      ^~~~~~~~~~~~~~
      |                      ffi_raw_closure
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/src/powerpc/ffi_darwin.c:1172:31: error: unknown type name 'ffi_go_closure'; did you mean 'ffi_raw_closure'?
 1172 | ffi_go_closure_helper_DARWIN (ffi_go_closure*, void *,
      |                               ^~~~~~~~~~~~~~
      |                               ffi_raw_closure
/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_ecl/ecl/work/ecl-24.5.10/src/libffi/src/powerpc/ffi_darwin.c:1434:31: error: unknown type name 'ffi_go_closure'; did you mean 'ffi_raw_closure'?
 1434 | ffi_go_closure_helper_DARWIN (ffi_go_closure *closure, void *rvalue,
      |                               ^~~~~~~~~~~~~~
      |                               ffi_raw_closure
make[3]: *** [src/powerpc/ffi_darwin.lo] Error 1
make[3]: Leaving directory `/opt/local/var/macports/build/ecledd528/work/ecl-24.5.10/build/libffi'
make[2]: *** [install-recursive] Error 1
make[2]: Leaving directory `/opt/local/var/macports/build/ecledd528/work/ecl-24.5.10/build/libffi'
make[1]: *** [libeclffi.a] Error 2
make[1]: Leaving directory `/opt/local/var/macports/build/ecledd528/work/ecl-24.5.10/build'
make: *** [all] Error 2