Avoid name collision with __atomic_compare_exchange.

gistfile1.diff

--- db-4.8.26/dbinc/atomic.h.orig  2013-02-12 11:47:58.000000000 +0100
+++ db-4.8.26/dbinc/atomic.h	2013-02-12 11:49:24.000000000 +0100
@@ -144,7 +144,7 @@
 #define	atomic_inc(env, p)	__atomic_inc(p)
 #define	atomic_dec(env, p)	__atomic_dec(p)
 #define	atomic_compare_exchange(env, p, o, n)	\
-	__atomic_compare_exchange((p), (o), (n))
+	__db_atomic_compare_exchange((p), (o), (n))
 static inline int __atomic_inc(db_atomic_t *p)
 {
 	int	temp;
@@ -176,7 +176,7 @@
  * http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html
  * which configure could be changed to use.
  */
-static inline int __atomic_compare_exchange(
+static inline int __db_atomic_compare_exchange(
 	db_atomic_t *p, atomic_value_t oldval, atomic_value_t newval)
 {
 	atomic_value_t was;