intel/compiler: Add support for the LSC

Xe-HPG comes with a massively reworked dataport. The new thing, now called LSC, has a significantly improved interface. Instead of bespoke messages for every case, there's basically one or two messages with different bits to control things like address size, how much data is read/written, etc. It's way nicer but also means we get to rewrite all our dataport encoding/decoding code.