message: fix(makefile) Add a default value to `use_system_ffi`.
diff: @@ -234,8 +234,7 @@ compilers_engines := $(strip $(compilers_engines))
  # system itself.
  #
  # See <https://github.com/libffi/libffi/pull/621>.
  -
  -use_system_ffi :=
  +use_system_ffi := 0
  ifeq ($(IS_DARWIN), 1)
  ifeq ($(IS_AARCH64), 1)
  