OpenLibm has an implementation of fenv.h internally. This may be
problematic in case you want it to build against the host system's
implementation, as it would require you to somehow take the fenv.h file
out of the compiler search path.
Simply use a different naming scheme, similar to openlibm.h and
openlibm_complex.h. If we want to build against the host's fenv.h, we
can simply add an '#include <fenv.h>' from within this header.
Instead of using all sorts of operating system specific constructs, we
can just query the compiler which byte order is being used. This has the
advantage that the code builds on new platforms without any tweaks.
<sys/cdefs.h> is not a standard header. Instead, we'd better pull in a
common header like <stdio.h>. It is very likely that such a header
already provides the necessary bits.
skip END and add .drectve export in assembly versions
uncomment __strong_reference definition from cdefs-compat.h
use weak references in place of strong references on Mac
add DLLEXPORT to all strong references
Fixes Julia issue #6777
