[LTP] [PATCH V2 21/32] Define _GNU_SOURCE for MREMAP_MAYMOVE definition

[Cyril Hrubis]

Hi!
> musl guards MREMAP_MAYMOVE with _GNU_SOURCE unlike glibc which uses
> __USE_GNU
> 
> Fixes errors like
> error: 'MREMAP_MAYMOVE' undeclared (first use in this function)

This will break on glibc. The correct solution is to define the
_GNU_SOURCE before we include any headers and there is no point in
undefining it later. And the __USE_GNU is glibc internal macro that
should not be set at all...

-- 
Cyril Hrubis
chrubis@suse.cz