This adds two defines that are missing on AIX because they don't have
the endian.h header file. AIX is always big endian, so no further check
is required for that. As I have no access to IBMs XLC compiler, this
patch limits the definitions to GNU GCC.
#include <endian.h>
#elif HAVE_SYS_ENDIAN_H
#include <sys/endian.h>
#include <endian.h>
#elif HAVE_SYS_ENDIAN_H
#include <sys/endian.h>
+#elif defined(_AIX) && defined(__GNUC__)
+/* AIX is always big endian */
+#define be16toh(x) (x)
+#define be64toh(x) (x)