It doesn’t matter. Even if the person asked explicitly being that he has no right to commit suicide there is no right to kill him if he asks. See Physician – Assisted Suicide: A Halachic Approach by Rabbi Yitzchok Breitowitz. Note that David ordered the ger Amaleki executed for killing Shaul at the latter’s request.
There is even a machloket regarding someone who gives permission to hit him. Some say that the hitter is over on a lav (Responsa Chavat Yair 163, Shulchan Aruch HaRav 5 Hilchot Nizkei HaGuf 4, Chazon Ish CM 19:5) being that a person is not the owner of his body, Hashem is. Others say that he is not over (Responsa Mahalbach Kuntras HaSemicha Kuntras Rishon d”h od, Minchat Chinuch Mitzva 48 Ot 3 as this is a matter of monetary damages and, in the case of parents, their personal honor).