user: implement mlibc as the libc, finally.

It's finally done..

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

user/include/mlibc/options/linux/generic/sys-statfs.cpp

@@ -0,0 +1,28 @@
+
+#include <errno.h>
+#include <sys/statfs.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/linux-sysdeps.hpp>
+
+int statfs(const char *path, struct statfs *buf) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_statfs, -1);
+	if(int e = mlibc::sys_statfs(path, buf); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fstatfs(int fd, struct statfs *buf) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fstatfs, -1);
+	if (int e = mlibc::sys_fstatfs(fd, buf); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+[[gnu::alias("fstatfs")]] int fstatfs64(int, struct statfs64 *);
+