add libc gethostbyname test

tests/test_gethostbyname.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <netdb.h>
+#include "../src/common.c"
+
+void printhostent(struct hostent *hp) {
+	char ipbuf[16];
+	pc_stringfromipv4(hp->h_addr_list[0], ipbuf);
+	printf("alias: %p, len: %d, name: %s, addrlist: %p, addrtype: %d, ip: %s\n", 
+		hp->h_aliases, 
+		hp->h_length,
+		hp->h_name,
+		hp->h_addr_list,
+		hp->h_addrtype,
+		ipbuf
+	);
+}
+int main(int argc, char**argv) {
+	struct hostent* ret;
+	if(argc == 1) return 1;
+	ret = gethostbyname(argv[1]);
+	if(ret) printhostent(ret);
+	return 0;
+}