build: add a "user" arch to allow the kernel to run as a program on the host machine

arch/user/stdcon.c

@@ -0,0 +1,27 @@
+#include <socks/libc/string.h>
+#include <socks/libc/ctype.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <socks/console.h>
+#include <socks/vm.h>
+#include <socks/printk.h>
+
+static void stdcon_write(console_t *con, const char *s, unsigned int len)
+{
+	for (unsigned int i = 0; i < len; i++) {
+		fputc(s[i], stdout);
+	}
+}
+
+static console_t stdcon = {
+	.c_name = "stdcon",
+	.c_flags = CON_BOOT,
+	.c_write = stdcon_write,
+	.c_lock = SPIN_LOCK_INIT,
+};
+
+void stdcon_init(void)
+{
+	console_register(&stdcon);
+	early_printk_init(&stdcon);
+}