Change __OPTIMIZE__ > 0 to defined(__OPTIMIZE__) as in glibc-2.3.5.

include/features.h

@@ -266,7 +266,7 @@
 # define __USE_REENTRANT	1
 #endif
 
-#if _FORTIFY_SOURCE > 0 && __GNUC_PREREQ (4, 1) && __OPTIMIZE__ > 0
+#if _FORTIFY_SOURCE > 0 && __GNUC_PREREQ (4, 1) && defined(__OPTIMIZE__)
 # if _FORTIFY_SOURCE == 1
 #  define __USE_FORTIFY_LEVEL 1
 # elif _FORTIFY_SOURCE > 1