Re: New to XC8 & I have a question ...
You've gone through every header MCC is referencing - including xc.h ? Still asking ?
To cut things short: the compiler comes with a processor-specific include file for each and every derivative. Usual names are either the full derivative's name (picC16fxxxxx.h) or a shortened form "p16fxxxxx.h". The same scheme applies for the assembly includes *.inc. All to be found in the compiler's installation path.
PEBKAC / EBKAC / POBCAK / PICNIC (eventually see en.wikipedia.org)