add unit test case for pcap dependency object

test cases/frameworks/19 pcap/meson.build

@@ -0,0 +1,7 @@
+project('pcap test', 'c')
+
+pcap_dep = dependency('pcap', version : '>=1.0')
+
+e = executable('pcap_prog', 'pcap_prog.c', dependencies : pcap_dep)
+
+test('pcaptest', e)

test cases/frameworks/19 pcap/pcap_prog.c

@@ -0,0 +1,9 @@
+#include <pcap/pcap.h>
+
+int
+main()
+{
+    char errbuf[PCAP_ERRBUF_SIZE];
+    pcap_t *p = pcap_create(NULL, errbuf);
+    return p == NULL;
+}