[Ecls-list] Adding AO_REQUIRE_CAS before libatomic-ops include

[Christoph Egger]

Hi folks!

  Please consider the attached patch. It enables CAS emulation on
systems, that do not have native CAS instructions (?!), which is, for
example, true on ARM < ARMv6

  Christoph

--- a/src/h/internal.h
+++ b/src/h/internal.h
@@ -422,6 +422,7 @@ extern void cl_write_object(cl_object x, cl_object stream);
 #endif /* ECL_THREADS */
 
 #ifdef ECL_THREADS
+# define AO_REQUIRE_CAS
 # ifdef ECL_LIBATOMIC_OPS_H
 #  include <ecl/atomic_ops.h>
 # else