Make execle() and chown() available again (corrects commit 15179).

libc/sysdeps/linux/common/chown.c

@@ -25,3 +25,4 @@ int chown(const char *path, uid_t owner, gid_t group)
 	}
 	return (__syscall_chown(path, owner, group));
 }
+libc_hidden_def(chown)

libc/unistd/exec.c

@@ -179,6 +179,7 @@ int execle(const char *path, const char *arg, ...)
 
 	return n;
 }
+libc_hidden_def(execle)
 
 #endif
 /**********************************************************************/