make ARRAY_SIZE commonly available internally

Some places have opencoded the ARRAY_SIZE macro, so move it to a global
internal location so other places can leverage it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

include/libc-internal.h

@@ -74,6 +74,8 @@ libc_hidden_proto(__chk_fail)
 
 #endif /* __ASSEMBLER__ */
 
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
 /* Some people like to build up uClibc with *-elf toolchains, so
  * a little grease here until we drop '#ifdef __linux__' checks
  * from our source code.

libc/inet/resolv.c

@@ -352,9 +352,6 @@ Domain name in a message can be represented as either:
 #define DPRINTF(X,args...)
 #endif
 
-#undef ARRAY_SIZE
-#define ARRAY_SIZE(v) (sizeof(v) / sizeof((v)[0]))
-
 /* Make sure the incoming char * buffer is aligned enough to handle our random
  * structures.  This define is the same as we use for malloc alignment (which
  * has same requirements).  The offset is the number of bytes we need to adjust