user: implement mlibc as the libc, finally.

It's finally done..

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

user/include/mlibc/sysdeps/astral/generic/astral.cpp

@@ -0,0 +1,15 @@
+#include <astral/syscall.h>
+#include <astral/archctl.h>
+#include <errno.h>
+
+#ifndef MLIBC_BUILDING_RTLD
+
+int arch_ctl(int func, void *arg) {
+	long ret;
+	long error = syscall(SYSCALL_ARCHCTL, &ret, func, (uint64_t)arg);
+	if(error)
+		errno = error;
+	return error ? -1 : ret;
+}
+
+#endif