* gendef (sigdelayed): Make sure to align the stack since sigdelayed
	can be called with or without aligned stack.  Save and restore all
	CPU registers.
	* exceptions.cc (stack_info::init): Don't attempt to dereference NULL
	framep.
	(exception::handle): On x86_64, if Rbp is NULL, use Rsp as frame
	pointer.
	* lib/_cygwin_crt0_common.cc: Fix mangled operator new names for x86_64.