Mark XLC atomics as non-inline.

This commit was SVN r16989.

opal/include/opal/sys/powerpc/atomic.h

@@ -96,6 +96,9 @@ void opal_atomic_wmb(void)
  * containing the right hex for the instructions).
  */
 
+#undef OPAL_HAVE_INLINE_ATOMIC_MEM_BARRIER
+#define OPAL_HAVE_INLINE_ATOMIC_MEM_BARRIER 0
+
 #pragma mc_func opal_atomic_mb { "7c0004ac" }          /* sync  */
 #pragma reg_killed_by opal_atomic_mb                   /* none */