libpcap: -Werror=implicit-function-declaration

packages/libpcap/optimize.c.patch

@@ -0,0 +1,12 @@
+diff -u -r ../libpcap-1.8.1/optimize.c ./optimize.c
+--- ../libpcap-1.8.1/optimize.c	2016-10-26 00:07:59.000000000 +0000
++++ ./optimize.c	2017-07-06 23:14:39.055350334 +0000
+@@ -66,7 +66,7 @@
+ /*
+  * So is the check for _MSC_VER done because MinGW has this?
+  */
+-#if defined(_WIN32) && defined (_MSC_VER)
++#if (defined(_WIN32) && defined (_MSC_VER)) || defined(__ANDROID__)
+ /*
+  * ffs -- vax ffs instruction
+  *