user: implement mlibc as the libc, finally.

It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

user/include/mlibc/tests/posix/getservbyport.c

@@ -0,0 +1,28 @@
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+
+int main() {
+	struct servent *ret = getservbyport(htons(80), "tcp");
+	assert(ret);
+	assert(!strcmp("http", ret->s_name));
+	assert(ret->s_port == htons(80));
+	assert(!strcmp("tcp", ret->s_proto));
+
+	ret = getservbyport(htons(80), NULL);
+	assert(ret);
+	assert(!strcmp("http", ret->s_name));
+	assert(ret->s_port == htons(80));
+	assert(!strcmp("tcp", ret->s_proto));
+
+	ret = getservbyport(htons(6696), "udp");
+	assert(ret);
+	ret = getservbyport(htons(6696), "tcp");
+	assert(!ret);
+
+	ret = getservbyport(htons(0), NULL);
+	assert(!ret);
+	return 0;
+}