Bug #50877 Windows version of my_dir() does not set the MY_S_IFREG bit for regular files

Description:
After calling my_dir() to get info on the files in a directory, I try to check if it's not a regular file:

  if (!MY_S_ISREG(file->mystat->st_mode))

This does not work on Windows (this negative test is always true), and I can see from the Win version of the code that it doesn't set the MY_S_IFREG bit.

I needed this for the Windows port of the fix for Bug #39774. A workaround is to instead do:

  if (MY_S_ISDIR(file->mystat->st_mode))

, because the MY_S_IFDIR bit is set. Should be safe enough in this context.

How to repeat:
Get info from a directory that contains regular files using my_dir, then check the mystat->st_mode of each file

Thank you for the report.

Verified as described.