Hand-crafted! I use famitracker, so bends have to be done manually. You put in a direction, speed, and amount of semitones. Vibrato is done by setting amplitude and wavelength at each line. The real necessary part was putting a very slight (like talking percents of a tone) shift on the secondary rhythm melody channels, along with a very slight long-period vibrato, to prevent any pitch intersections. If you don't adjust for that, you end up with sour notes.

I've been using famitracker for ten years, it takes a while to pick the stuff up but it can be done.