I realize this is a bit proactive, but... From glibc upstream:
"In some future release, glibc's <sys types.h=""> will not include <sys sysmacros.h=""> anymore. As of 2.25, it still does, but you get deprecation warnings if you use the macros without including <sys sysmacros.h="">. We have not decided exactly which future release will finally remove the #include; to help us decide, please send reports of software that trips the deprecation warnings to libc-alpha."</sys></sys></sys>
autoconf already has AC_HEADER_MAJOR, which sets MAJOR_IN_SYSMACROS if the sys/sysmacros.h include is needed.
The macros are at least used in gpib_config.c.
References:
https://sourceware.org/ml/libc-alpha/2015-11/msg00253.html
https://bugzilla.redhat.com/show_bug.cgi?id=130601
https://bugs.gentoo.org/show_bug.cgi?id=575232
Thanks Andreas.
glibc-2.28 was released with sys/sysmacros.h removed from sys/types.h