access X_OK for administrators has changed in cygwin 3.5.5

[Bruno Haible]

Hi,

The behaviour of the access(_, X_OK) call has changed for administrator
users in Cygwin 3.5.5. I don't know whether that's intended or not
(haven't seen it mentioned in
<https://sourceware.org/pipermail/cygwin-announce/2024-December/012023.html>).

How to reproduce:
========================== foo.c ===========================
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <grp.h>
#include <unistd.h>
int main ()
{
  close (creat ("file", 0600));
  chmod ("file", 0400);
  printf ("file X_OK ? %d\n", access ("file", X_OK));
}
============================================================
1. In a normal Cygwin console (mintty):
   $ rm -f file
   $ gcc -Wall foo.c
   $ ./a
   => file X_OK ? -1
2. In a Cygwin console that runs "as administrator":
   $ ./a
   => In Cygwin 3.4.6: file X_OK ? -1
      In Cygwin 3.5.5: file X_OK ? 0

Bruno