O_CLOEXEC is always defined for arm, mips, x86, and x86_64.

I built all four, just to be sure.

Change-Id: I5c818575c8142fccfc8fb163468832807a535e90

libc/include/fcntl.h

@@ -25,6 +25,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #ifndef _FCNTL_H
 #define _FCNTL_H
 
@@ -39,10 +40,6 @@ __BEGIN_DECLS
 #define O_ASYNC  FASYNC
 #endif
 
-#ifndef O_CLOEXEC
-#define O_CLOEXEC  02000000
-#endif
-
 extern int  open(const char*  path, int  mode, ...);
 extern int  openat(int fd, const char*  path, int  mode, ...);
 extern int  unlinkat(int dirfd, const char *pathname, int flags);