Cygwin: pty, console: Fix deadlock in GDB regarding mutex.

Cygwin: pty, console: Fix deadlock in GDB regarding mutex.

- GDB inferior may be suspended while the inferior grabs mutex.
  This causes deadlock in terminal I/O. With this patch, timeout
  for waiting mutex is set to 0 for the debugger process when the
  process calls CreateProcess() with DEBUG_PROCESS flag to avoid
  deadlock. This may cause the race issue in GDB, however, there
  is no other way than that.

Addresses:
 https://cygwin.com/pipermail/cygwin-developers/2021-December/012542.html