Define __WORDSIZE like glibc.

Requested by Google Breakpad, but seems to be assumed to be defined
in various places in the AOSP tree already; iputils, wpa_supplicant,
et cetera.

Change-Id: I1f7833c98e0af4c77e49744c08b8239061c9a571

libc/include/sys/cdefs.h

@@ -528,6 +528,13 @@
 #define  __BIONIC__   1
 #include <android/api-level.h>
 
+/* glibc compatibility. */
+#if __LP64__
+#define __WORDSIZE 64
+#else
+#define __WORDSIZE 32
+#endif
+
 /*
  * When _FORTIFY_SOURCE is defined, automatic bounds checking is
  * added to commonly used libc functions. If a buffer overrun is