Description: We need __EXTENSIONS__ if _GNU_SOURCE is defined
Index: b/usr/src/head/stdio.h
===================================================================
--- a/usr/src/head/stdio.h
+++ b/usr/src/head/stdio.h
@@ -34,7 +34,7 @@
 #ifndef _STDIO_H
 #define	_STDIO_H
 
-#include <sys/feature_tests.h>
+#include <features.h>
 
 #ifdef	__cplusplus
 extern "C" {