Revert "Fix PR 67102: Add libstdc++ dependancy to libffi" [PR67102]

This reverts commit db1a65d9.

On 2021-09-17T01:01:39-0700, Andrew Pinski via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> On Fri, Sep 17, 2021 at 12:46 AM Thomas Schwinge <thomas@codesourcery.com> wrote:
>> On 2021-09-15T13:56:37-0700, apinski--- via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
>> > The error message is obvious -funconfigured-libstdc++-v3 is used
>> > on the g++ command line.  So we just add the dependancy.
>>
>> > --- a/Makefile.def
>> > +++ b/Makefile.def
>> > @@ -592,6 +592,7 @@ dependencies = { module=configure-target-fastjar; on=configure-target-zlib; };
>> >  dependencies = { module=all-target-fastjar; on=all-target-zlib; };
>> >  dependencies = { module=configure-target-libgo; on=configure-target-libffi; };
>> >  dependencies = { module=configure-target-libgo; on=all-target-libstdc++-v3; };
>> > +dependencies = { module=configure-target-libffi; on=all-target-libstdc++-v3; };
>> >  dependencies = { module=all-target-libgo; on=all-target-libbacktrace; };
>> >  dependencies = { module=all-target-libgo; on=all-target-libffi; };
>> >  dependencies = { module=all-target-libgo; on=all-target-libatomic; };
>>
>> I'm confused, because given that this 'Makefile.def' change only has the
>> following effect:
>>
>> > --- a/Makefile.in
>> > +++ b/Makefile.in
>> > @@ -61261,6 +61261,7 @@ all-bison: maybe-all-intl
>> >  all-flex: maybe-all-intl
>> >  all-m4: maybe-all-intl
>> >  configure-target-libgo: maybe-all-target-libstdc++-v3
>> > +configure-target-libffi: maybe-all-target-libstdc++-v3
>> >  configure-target-liboffloadmic: maybe-configure-target-libgomp
>> >  all-target-liboffloadmic: maybe-all-target-libgomp
>> >  configure-target-newlib: maybe-all-binutils
>>
>> ... isn't that actually a no-op, because we already had such a dependency
>> listed?  Now twice:
>>
>>     $ grep -n -F 'configure-target-libffi: maybe-all-target-libstdc++-v3' -- Makefile.in
>>     61264:configure-target-libffi: maybe-all-target-libstdc++-v3
>>     61372:configure-target-libffi: maybe-all-target-libstdc++-v3
>>
>> Compared to the existing one, the one you've added is additionally
>> restricted by '@unless gcc-bootstrap'.
>>
>> I noticed this as I remembered that on our og[...] development branches
>> we have a patch in the opposite direction: get rid of this dependency via
>> removing 'lang_env_dependencies = { module=libffi; cxx=true; };' from
>> 'Makefile.def'.  See
>> <http://mid.mail-archive.com/alpine.DEB.2.21.9999.1812201344250.99920@build7-trusty-cs.sje.mentorg.com>
>> "Disable libstdc++ dependency for libffi".  (Maciej CCed in case you have
>> any further thoughts on that.)
>
> Oh, I see what happened now, the old bug was actually fixed by r6-5415
> which added cxx=true.
> So yes my patch is actually not needed and can be reverted.
> I tried to look to see if there was a dependency was there but for
> some reason I did not see it.