[Bug libstdc++/122322] [14/15/16 regression] libstdc++-v3 autoreconf broken since r16-4443-g651bf5126da124

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122322

--- Comment #3 from Sam James <sjames at gcc dot gnu.org> ---
There are also a bunch of duplicate entries there, like for HAVE_SYS_IOCT4YL_H
(just a few lines apart).