Add support for target helper functions which don't return Most functions which handle exceptions don't return. With a compiler attribute (added by QEMU_NORETURN), gcc can optimize the code. Signed-off-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>