Minor fixes + cleanup in os2 and sys/linux

Add NOFOLLOW to os2.remove
Change Dev from int to u64 and make relavant casts
Fix compat64_arg_pair

core/os/os2/file_linux.odin

@@ -275,7 +275,7 @@ _remove :: proc(name: string) -> Error {
 	TEMP_ALLOCATOR_GUARD()
 	name_cstr := temp_cstring(name) or_return
 
-	if fd, errno := linux.open(name_cstr, _OPENDIR_FLAGS); errno == .NONE {
+	if fd, errno := linux.open(name_cstr, _OPENDIR_FLAGS + {.NOFOLLOW}); errno == .NONE {
 		linux.close(fd)
 		return _get_platform_error(linux.rmdir(name_cstr))
 	}

core/os/os2/path_linux.odin

@@ -77,8 +77,6 @@ _mkdir_all :: proc(path: string, perm: int) -> Error {
 }
 
 _remove_all :: proc(path: string) -> Error {
-	DT_DIR :: 4
-
 	remove_all_dir :: proc(dfd: linux.Fd) -> Error {
 		n := 64
 		buf := make([]u8, n)

core/sys/linux/helpers.odin

@@ -139,7 +139,7 @@ when size_of(int) == 4 {
 	// xxx64 system calls take some parameters as pairs of ulongs rather than a single pointer
 	@(private)
 	compat64_arg_pair :: #force_inline proc "contextless" (a: i64) -> (hi: uint, lo: uint) {
-		no_sign := uint(a)
+		no_sign := u64(a)
 		hi = uint(no_sign >> 32)
 		lo = uint(no_sign & 0xffff_ffff)
 		return

core/sys/linux/sys.odin

@@ -1952,10 +1952,10 @@ sigaltstack :: proc "contextless" (stack: ^Sig_Stack, old_stack: ^Sig_Stack) ->
 */
 mknod :: proc "contextless" (name: cstring, mode: Mode, dev: Dev) -> (Errno) {
 	when ODIN_ARCH == .arm64 || ODIN_ARCH == .riscv64 {
-		ret := syscall(SYS_mknodat, AT_FDCWD, cast(rawptr) name, transmute(u32) mode, dev)
+		ret := syscall(SYS_mknodat, AT_FDCWD, cast(rawptr) name, transmute(u32) mode, cast(uint) dev)
 		return Errno(-ret)
 	} else {
-		ret := syscall(SYS_mknod, cast(rawptr) name, transmute(u32) mode, dev)
+		ret := syscall(SYS_mknod, cast(rawptr) name, transmute(u32) mode, cast(uint) dev)
 		return Errno(-ret)
 	}
 }
@@ -2586,7 +2586,7 @@ mkdirat :: proc "contextless" (dirfd: Fd, name: cstring, mode: Mode) -> (Errno)
 	Available since Linux 2.6.16.
 */
 mknodat :: proc "contextless" (dirfd: Fd, name: cstring, mode: Mode, dev: Dev) -> (Errno) {
-	ret := syscall(SYS_mknodat, dirfd, cast(rawptr) name, transmute(u32) mode, dev)
+	ret := syscall(SYS_mknodat, dirfd, cast(rawptr) name, transmute(u32) mode, cast(uint) dev)
 	return Errno(-ret)
 }
 

core/sys/linux/types.odin

@@ -3,7 +3,7 @@ package linux
 /*
 	Type for storage device handle.
 */
-Dev :: distinct int
+Dev :: distinct u64
 
 /*
 	Type for 32-bit User IDs.
@@ -153,6 +153,7 @@ when ODIN_ARCH == .amd64 {
 		uid:        Uid,
 		gid:        Gid,
 		rdev:       Dev,
+		_:          [4]u8,
 		size:       i64,
 		blksize:    uint,
 		blocks:     u64,