Set bridge to Opaque
Set abstractionType LibraryRefs
Add support for AddressSpaces and "fixed" MemoryMaps (needs generalizing).
Add support for Views.

Safer crossings

Adjusted to include names for the new registers.
Changes to RegisterCrossing were discarded.

If the other clock domain is much faster than ours, it's reset
might be shorter than a single cycle in our domain. In that case,
we need to catch the reset and extend it.

There is no need to block writes to mem during reset.
The Queue must be empty anyway.

This seems to be the more common API