Use gcc build-in atomic functions,
the selfmade versions will not work on powerpc

---
 include/private/gc_locks.h |   13 +++++++++++++
 1 file changed, 13 insertions(+)

--- a/include/private/gc_locks.h
+++ b/include/private/gc_locks.h
@@ -88,6 +88,18 @@
 /* acquisition and release.  We need this for correct operation of the	*/
 /* incremental GC.							*/
 #  ifdef __GNUC__
+#if __GNUC__ >= 4 && __GNUC_MINOR__ >= 1
+static inline int GC_test_and_set(volatile unsigned int *addr)
+{
+#define GC_TEST_AND_SET_DEFINED
+       return (int)__sync_lock_test_and_set(addr, 1);
+}
+static inline void GC_clear(volatile unsigned int *addr)
+{
+#define GC_CLEAR_DEFINED
+       __sync_lock_test_and_set(addr, 0);
+}
+#else /* ! __GNUC__ 4.1+ */
 #    if defined(I386)
        inline static int GC_test_and_set(volatile unsigned int *addr) {
 	  int oldval;
@@ -288,6 +300,7 @@
          return ret;
        }
 #    endif
+#   endif /* !__GNUC__ 4.1+ */
 #  endif /* __GNUC__ */
 #  if (defined(ALPHA) && !defined(__GNUC__))
 #    ifndef OSF1