In the gallium code, the assert() macro could come from either the
system's assert.h file (via c11/threads.h) or from gallium's u_debug.h.
It looks like all known assert.h files unconditionally #undef assert
before defining their own version. So the assert you get depends on
whether threads.h or u_debug.h was included last.
In the gallium code we really want to use the assert() from u_debug.h
(it behaves better on Windows). In gallium, c11/threads.h is only
included after u_debug.h in the os_thread.h wrapper. So Adding
an #ifndef assert test in the threads*.h files avoids using the system's
Cc: "10.1" <firstname.lastname@example.org>
Reviewed-by: José Fonseca <email@example.com>