Before, we only checked the callee for swifterror. However, we should also be checking the caller to see if it has a swifterror parameter.
Since we don't currently handle outgoing arguments, this didn't show up in the swifterror.ll testcase. (It did show up when I started implementing outgoing arguments though.)
Also, remove the swifterror checks from call-translator-tail-call.ll, since they are covered by the existing swifterror testing. Better to have it all in one place.