minor problem with DEBUGGING build of Cygwin

[Mark Geisert]

Hi folks,
I've built the Cygwin DLL tonight (though not with the absolute latest git 
HEAD) with DEBUGGING set and am seeing output like...

74972684 [main] -bash 1153 close_handle: CloseHandle(pi->bye<0x0>) failed 
void pty_slave_cleanup(select_record*, select_stuff*):1348, Win32 error 6

...displayed for each character I'm typing on the keyboard.  This is 
coming from select.cc:1348, which reads "CloseHandle (pi->bye);".  Win32 
error 6 is INVALID_HANDLE_VALUE.

If this is expected, I'll just keep pressing ^L to clean up the display. 
I thought I'd mention it in case it points to something malfunctioning.

..mark