* cygwin64.din (strlwr): Export.
	* cygwin.sc.in: Fix comment.
	* dcrt0.cc (child_info_fork::handle_fork): Revert patch from 2013-03-15.
	* 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.