This is a second patch needing another review.  The first patch didn't solve
the entire problem.  open and fopen on Windows will still open
files like "com1.sym" when they shouldn't.  This patch
checks that the file exists before trying to open it.



mysys/my_fopen.c:
  on Windows, if we are not creating a file the we call my_access to make sure the
  file exists before trying to open it.
mysys/my_open.c:
  on Windows, if we are not creating a file the we call my_access to make sure the
  file exists before trying to open it.