bug#2607: 23.0.90; `system-type' test in `shell-quote-wildcard-pattern'

This is not so much a bug report as a report of a possible bug, or at
least a question.
 
The code of `shell-quote-wildcard-pattern' has this test:
(memq system-type '(ms-dos windows-nt cygwin)).  Looking at that
code, the inclusion of `cygwin' here seems suspect to me.
 
The Elisp manual says only that a `system-type' of `cygwin' means
Emacs running on Cygwin ("type of operating system Emacs is operating
on"). Dunno what that means, really, but I'm guessing that such a
system would use a shell, such as `bash', that treats characters in
file names similarly to how `bash' treats them for GNU/Linux or UNIX.
 
I use Emacs on Windows, but not built on Cygwin. I use it with Cygwin
and with `bash' as my shell, however, and that is how the shell
behaves for me.  I have no problem with `shell-quote-wildcard-pattern'
AFAIK (my `system-type' is `windows-nt'), but I'm guessing that
someone with a `system-type' of `cygwin' might have trouble with it.
 
If these guesses are wrong, then please ignore this report.
 
If these guesses are correct, then perhaps `cygwin' should be removed
from that `system-type' test. The code would then treat `cygwin' Emacs
like Emacs on UNIX or GNU/Linux, as far as quoting file-name chars in
shell commands is concerned.
 

In GNU Emacs 23.0.90.1 (i386-mingw-nt5.1.2600)
 of 2009-02-01 on SOFT-MJASON
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4)'