show that shm communication still works on windows,
and that we can't overflow the base-name.


mysql-test/t/windows_shm-master.opt:
  Bug#24924: shared-memory-base-name that is too long causes buffer overflow
  
  start a server with shm communication if we're on
  windows.
mysql-test/t/windows_shm.test:
  Bug#24924: shared-memory-base-name that is too long causes buffer overflow
  
  .opt has started a server with shm communication
  if we're on windows. now start a client with shm
  and connect to that server.