Added missing API function declaration.

ext/standard/file.h

@@ -72,6 +72,7 @@ PHP_MINIT_FUNCTION(user_streams);
 PHPAPI int php_le_stream_context(void);
 PHPAPI int php_set_sock_blocking(int socketd, int block TSRMLS_DC);
 PHPAPI int php_copy_file(char *src, char *dest TSRMLS_DC);
+PHPAPI int php_copy_file_ex(char *src, char *dest, int src_chk TSRMLS_DC);
 PHPAPI int php_mkdir_ex(char *dir, long mode, int options TSRMLS_DC);
 PHPAPI int php_mkdir(char *dir, long mode TSRMLS_DC);
 PHPAPI void php_fgetcsv(php_stream *stream, char delimiter, char enclosure, size_t buf_len, char *buf, zval *return_value TSRMLS_DC);