[Bug preprocessor/97998] GCC should not complain about double definitions of macros whose names begin with __STDC_

[zackw at panix dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97998

--- Comment #1 from Zack Weinberg <zackw at panix dot com> ---
For more information see Autoconf bug report
<https://savannah.gnu.org/support/?110382> and APR pull request
<https://github.com/apache/apr/pull/25>.