syscall: let errors.ErrUnsupported match ERROR_NOT_SUPPORTED and ERROR_CALL_NOT_IMPLEMENTED

These error codes are returned on windows in case a particular functions
is not supported.

Updates #41198

Change-Id: Ic31755a131d4e7c96961ba54f5bb51026fc7a563
Reviewed-on: https://go-review.googlesource.com/c/go/+/476916
Auto-Submit: Tobias Klauser <[email protected]>
Reviewed-by: Bryan Mills <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Run-TryBot: Tobias Klauser <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

Author: tklauser

src/syscall/syscall_windows.go

@@ -142,7 +142,11 @@ func (e Errno) Error() string {
 	return string(utf16.Decode(b[:n]))
 }
 
-const _ERROR_BAD_NETPATH = Errno(53)
+const (
+	_ERROR_NOT_SUPPORTED        = Errno(50)
+	_ERROR_BAD_NETPATH          = Errno(53)
+	_ERROR_CALL_NOT_IMPLEMENTED = Errno(120)
+)
 
 func (e Errno) Is(target error) bool {
 	switch target {
@@ -162,7 +166,9 @@ func (e Errno) Is(target error) bool {
 			e == ERROR_PATH_NOT_FOUND ||
 			e == ENOENT
 	case errorspkg.ErrUnsupported:
-		return e == ENOSYS ||
+		return e == _ERROR_NOT_SUPPORTED ||
+			e == _ERROR_CALL_NOT_IMPLEMENTED ||
+			e == ENOSYS ||
 			e == ENOTSUP ||
 			e == EOPNOTSUPP ||
 			e == EWINDOWS