* i686.din: New file.
* x86_64.din: New file.
* common.din: New file.
* cygwin.din: Delete.
* cygwin64.din: Delete.
* gendef: Rework to take options rather than using positional parameters.
Accept multiple files as input.
missing checkin
Sigh.  Another missing checkin.
* exceptions.cc (cygwin_exception::dumpstack): Guard against wild pointer
dereference.
(CYG_EXC_CONTINUE_EXECUTION): Define based on standard Windows definition.
(CYG_EXC_CONTINUE_SEARCH): Ditto.
(exception::handle): Move andreas detection earlier.  Make comment clearer.
(signal_exit): Set core-dumped flag.
* spawn.cc (system_call_cleanup): Rename from pthread_cleanup.  Extend
functionality.
(system_call_cleanup::system_call_cleanup): Set up signals like system()
requires.  Unblock previously-blocked signal handling.
(system_call_cleanup::~system_call_cleanup): Restore signal handling after
system().
(child_info_spawn::worker): Put signals on hold and use system_call_cleanup
class to set and restore signals rather than doing it prior to to running the
program.  Remove the ill-conceived pthread_cleanup stuff.
* gendef: Fix sigfe.s typo.
Throughout, (mainly in fhandler*) fix remaining gcc 4.7 mismatch
warnings between regparm definitions and declarations.
* smallprint.cc (__small_vswprintf): Conditionalize declaration and
setting of l_opt for only x86_64.
* spawn.cc (child_info_spawn::worker): Remove unused 'pid' variable.
* thread.cc (verifyable_object_isvalid): Temporarily define as
non-inline with gcc 4.7+, regardless of target.