How many nails does it take to hang a picture of a suicidal person on the wall? None. It hangs itself.
Why would you joke about someone who is suicidal?
It's ok, I know someone who was suicidal.
Suicide is not something that should be joked about. It's a serious issue that people struggle dealing with everyday. You said you know a friend who was suicidal, so you should talk to them to try to get a better understanding of the difficulties they face.