I agree with you, and it's not necessarily letting them know BEFORE you arrive, you can at least tell them once you enter the room of the interview. like when they ask you to talk about yourself, you can say "before i talk about myself, i just wanna let you know that i stutter sometimes, and i can confirm that it won't affect my ability to do the job correctly. and when it happens(the stutter) i just need you to give me some time to finish my words.." then you go on and talk about yourself :)