_FORTIFY_SOURCE: add memset / bzero support

Add _FORTIFY_SOURCE support for the following functions:

* memset
* bzero

Move the __BIONIC_FORTIFY_INLINE definition to cdefs.h so it
can be used from multiple header files.

Change-Id: Iead4d5e35de6ec97786d58ee12573f9b11135bb7
diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h
index 71b419c..1ba9100 100644
--- a/libc/include/sys/cdefs.h
+++ b/libc/include/sys/cdefs.h
@@ -501,4 +501,12 @@
 #define  __BIONIC__   1
 #include <android/api-level.h>
 
+#if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
+#define __BIONIC_FORTIFY_INLINE \
+    extern inline \
+    __attribute__ ((always_inline)) \
+    __attribute__ ((gnu_inline)) \
+    __attribute__ ((artificial))
+#endif
+
 #endif /* !_SYS_CDEFS_H_ */