the problem is with plib
Yeah; in my mplab install, the library manual is pretty clearly titled "pic18_plib"...
This is probably the spot where someone should say:
DO NOT USE THE PIC16F84 ANY MORE !!!
While there are a lot of hobbyist projects and tutorials that use this chip, that is mostly a consequence of it having been one of the first flash-based microcontrollers readily available to hobbyists, back in 1993. Since then, Microchip has released MANY newer chips that have more memory, more peripherals, more modern architectural features, that are CHEAPER as well. If you search at microchip, you'll find that the 16F84A is THE *most expensive* chip in an 18pin dip that they have. You can get one of their 16bit dspic30 chips for less!