Debug: Added rf_reset signals needed by RF transform

Like 37a3161b,
this is also just for post-silicon debug purposes.  Disabling prefetch
doesn't add much extra PSD benefit beyond disabling speculative refill,
because the latter disables prefetching on speculative accesses already,
leaving only next-line prefetches following non-speculative refills.
But it is worth something.

AXIS fixes

Commit queue

Features
* Reset inference now supports last connect semantics

Fixes
* FirrtlOptions and CircuitOptions no longer serialized to anno JSON file

The user probably has this information already.

We already assert that enq.valid <= enq.ready

Improves mux control logic.