* dcrt0.cc (__argc_safe): New variable.

* dcrt0.cc (__argc_safe): New variable.
(dll_crt0_1): Store argc in __argc_safe, which will theoretically remain
untouched by the user.
* fhandler_console.cc (fhandler_console::read): Silence some compiler warnings.
* fhandler_raw.cc (fhandler_dev_raw::raw_read): Ditto.
* pinfo.cc (_pinfo::commune_recv): Carefully bound argv scan and check for
potentially bad pointers since user could have set argv cell to anythinw.
* cygheap.h (CYGHEAPSIZE): Bump up size.