avoid lots of warnings from clang

Index: ext/include/_helpers.c
--- ext/include/_helpers.c.orig
+++ ext/include/_helpers.c
@@ -90,7 +90,7 @@
 
 /* LPOSIX_STMT_BEG/END are used to create macros that expand to a
    single compound statement in a portable way. */
-#if defined __GNUC__ && !defined __STRICT_ANSI__ && !defined __cplusplus
+#if 0
 #  define LPOSIX_STMT_BEG	(void)(
 #  define LPOSIX_STMT_END	)
 #else
