Yep the ADCSAR is for AVR, sorry about that, it is all I really know at this point. But you can now look for some of those registers westfw has listed inside that p32mx795f512l.h file.
https://raw.githubusercontent.com/jasonkajita/pic32-part-support/master/include/proc/p32mx795f512l.h
Looking in that I see AD1PCFG has bit PCFG0 defined so things like
AD1PCFG = AD1PCFG | (1<<PCFG0); should compile.
If you look at the datasheet it should tell you about the AD1PCFG register and the PCFG0 bit does. This is the first I've looked at these so I'm not going to be much help.