illumos gate

From the code:

39  * PSARC 2004/405 made hat_getkpfnum(9F) obsolete. As part of the
     40  * obsolecense, the original documented behavior will begin to be
     41  * enforced in the future; namely, hat_getkpfnum(9F) may only
     42  * be called with device-mapped memory virtual addresses. Since
     43  * changing hat_getkpfnum(9F) to return PFN_INVALID on kernel memory
     44  * would break a lot of modules without any warning, we've implemented
     45  * the following mechanism as a stop-gap. In a future release, this
     46  * can all be ripped out and hat_getkpfnum(9F) changed to return
     47  * PFN_INVALID if it isn't called with a device-mapped memory address.

This has been this way for a long time now, and illumos is a logical time to go ahead and yank any references to this legacy API. In particular, this API has never been supported for 64-bit mode kernels.