bug#3328: set-default-file-modes on Windows Emacs broken

[Matthew Carter]

   * The version number of Emacs.

GNU Emacs 22.2.1 (i386-mingw-nt5.1.2600) of 2008-03-26 on RELEASE

   * The operands given to the configure command when Emacs was installed.

I installed this version of Windows emacs as a binary installation downloaded from the 
web, so I never ran a "configure" command.

   * A complete list of any modifications you have made to the Emacs source. 

None.

   * Details of any other deviations from the standard procedure for installing 
GNU Emacs.

None.

   * The precise commands we need to type to reproduce the bug.

Run this lisp expression:
 (set-default-file-modes ?\644)
e.g., by putting it in your ~/.emacs or by using M-:

Then, create a new file, "foo.txt".
Then, in a cygwin bash shell, run "ls -l foo.txt".
The file SHOULD have these permissions:
 -rw-r--r--
But instead, it has these permissions:
 -rwxrwxrwx


I tried passing various values to set-default-file-modes to see whether it had 
any effect at all.  It did, but not the expected effect.  Here are the results 
I found:

The first column tells the value that I passed in to set-default-file-modes .
The second column tells what value the default-file-modes function returned as 
a result.
The third column shows the actual permissions that a created file had (as shown by cygwin 
"ls -l").
(All values are shown in octal.)

     set-default-file-modes     default-file-modes     file permissions
     ----------------------     ------------------     ----------------
       01                       0177                   0555
     0700                       0777                   0755
     0777                       0777                   0755
        0                       0177                   0555
     0400                       0577                   0555
      040                       0177                   0555