Initial commit: Schunix as it stands before the SchOS rename

An x86-64 operating system built from xv6, now largely rewritten: SMP,
a copy-on-write root filesystem (SchFS), PCI/USB/virtio drivers, a TTF
rasteriser, and a Linux-numbered syscall ABI.

No history before this point -- the tree was never under version control.
This commit exists so the rename that follows has something to undo to.

include/stat.h

@@ -0,0 +1,24 @@
+#pragma once
+#include "types.h"
+
+#define T_DIR  1   // Directory
+#define T_FILE 2   // File
+#define T_DEV  3   // Device
+#define T_SYMLINK 4   // Divesymlink
+#define T_EXTENT  5   // bmap & itrunc
+
+struct stat {
+  int32  type;      // File type (T_DIR, T_FILE, or T_DEV)
+  int32  dev;       // File system's disk device ID
+  uint64 ino;       // Inode number
+  int32  nlink;     // Number of hard links to file
+  uint32 pad;       // Padding for 64-bit alignment
+  uint64 size;      // Size of file in bytes
+  uint rwmode;      // Permissions
+  uint supermode;   // Mode
+  uint showmode;    // Visiblity
+  uint atime;       // Last access time
+  uint mtime;       // Last modification time
+  uint ctime;       // Last metadata-change time
+  uint addrs[12+3]; // Block Addresses
+};