Define ino_t for systems not yet defining it

Also, use ino_t instead of u64 in fs.File.INode

lib/std/fs/file.zig

@@ -35,7 +35,7 @@ pub const File = struct {
         .windows => os.windows.LARGE_INTEGER,
         // TODO: Handle possibility of 128 bit numbers? ReFS on windows server 2012 uses a 128 bit file
         // index. See https://docs.microsoft.com/en-us/windows/win32/api/fileapi/ns-fileapi-by_handle_file_information
-        else => u64,
+        else => os.ino_t,
     };
 
     pub const default_mode = switch (builtin.os.tag) {

lib/std/os/bits/darwin.zig

@@ -53,6 +53,7 @@ pub const mach_timebase_info_data = extern struct {
 };
 
 pub const off_t = i64;
+pub const ino_t = u64;
 
 /// Renamed to Stat to not conflict with the stat function.
 /// atime, mtime, and ctime have functions to return `timespec`,
@@ -64,7 +65,7 @@ pub const Stat = extern struct {
     dev: i32,
     mode: u16,
     nlink: u16,
-    ino: u64,
+    ino: ino_t,
     uid: u32,
     gid: u32,
     rdev: i32,

lib/std/os/bits/dragonfly.zig

@@ -138,8 +138,10 @@ pub const MAP_SIZEALIGN = 262144;
 
 pub const PATH_MAX = 1024;
 
+pub const ino_t = c_ulong;
+
 pub const Stat = extern struct {
-    ino: c_ulong,
+    ino: ino_t,
     nlink: c_uint,
     dev: c_uint,
     mode: c_ushort,

lib/std/os/bits/freebsd.zig

@@ -98,6 +98,7 @@ pub const msghdr_const = extern struct {
 };
 
 pub const off_t = i64;
+pub const ino_t = u64;
 
 /// Renamed to Stat to not conflict with the stat function.
 /// atime, mtime, and ctime have functions to return `timespec`,
@@ -107,7 +108,7 @@ pub const off_t = i64;
 /// methods to accomplish this.
 pub const Stat = extern struct {
     dev: u64,
-    ino: u64,
+    ino: ino_t,
     nlink: usize,
 
     mode: u16,

lib/std/os/bits/linux/x86_64.zig

@@ -481,6 +481,7 @@ pub const msghdr_const = extern struct {
 };
 
 pub const off_t = i64;
+pub const ino_t = u64;
 
 /// Renamed to Stat to not conflict with the stat function.
 /// atime, mtime, and ctime have functions to return `timespec`,
@@ -490,7 +491,7 @@ pub const off_t = i64;
 /// methods to accomplish this.
 pub const Stat = extern struct {
     dev: u64,
-    ino: u64,
+    ino: ino_t,
     nlink: usize,
 
     mode: u32,

lib/std/os/bits/netbsd.zig

@@ -69,6 +69,7 @@ pub const msghdr_const = extern struct {
 };
 
 pub const off_t = i64;
+pub const ino_t = u64;
 
 /// Renamed to Stat to not conflict with the stat function.
 /// atime, mtime, and ctime have functions to return `timespec`,
@@ -79,7 +80,7 @@ pub const off_t = i64;
 pub const Stat = extern struct {
     dev: u64,
     mode: u32,
-    ino: u64,
+    ino: ino_t,
     nlink: usize,
 
     uid: u32,

lib/std/os/bits/wasi.zig

@@ -178,6 +178,7 @@ pub const FILESTAT_SET_MTIM: fstflags_t = 0x0004;
 pub const FILESTAT_SET_MTIM_NOW: fstflags_t = 0x0008;
 
 pub const inode_t = u64;
+pub const ino_t = inode_t;
 
 pub const linkcount_t = u32;