*win32-nat.c (open_process_used): New static variable.
(win32_init_thread_list): Remove call to CloseHandle for thread.
(win32_delete_thread): Ditto.
(fake_create_process): Set open_process_used if OpenProcess call is successful.
(get_win32_debug_event): Do not close process handle.
(do_initial_win32_stuff): Set open_process_used to zero.
(win32_mourn_inferior): Call CloseHandle for current_process_handle if
open_process_used is set.
(win32_kill_inferior): Do not close process and main_thread handles.