[flashrom-gerrit] Change in flashrom[master]: meson: fix compilation under uClibc-ng

[David Hendricks (Code Review)]

David Hendricks has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/43599 )

Change subject: meson: fix compilation under uClibc-ng
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Patch Set 1:

I'm curious if others have thoughts on how to best handle feature macros. Should we make the equivalent change in the Makefile and add -D_POSIX_C_SOURCE=200809L? We can instead set it in a commonly used header like platform.h. Or we can define it as needed on a file-by-file basis, but that might be ugly.

Also, if we add it to a header we can take the logic currently in dmi.c and do this:
#if (__GLIBC__ == 2 && __GLIBC_MINOR__ < 10) || __GLIBC__ < 2
#define _GNU_SOURCE
#else
#define _POSIX_C_SOURCE 200809L
#endif

Thoughts?