Probably murder, since he’s killing you. Suicide implies that you gotta do it yourself, and even assisted suicide demands a part of action on your behalf to be defined as such.
I suppose if some dude is willing to shoot you and you’re willing to let him do it, but by being aware of it at the moment, it’s assisted suicide, but if you don’t know when he’ll strike, the definition is lost there, no matter the intent/desire.