This PR introduces a missing pice of far atomic implementation. This
pull request incorporates several changes:
- Enable 2-level and 4-level (and N-level) cache hierarchies, removing
Atomic_NoWait transactions
- Fix Unique Near policy implementation that raised abort
- Add support for alloc_on_atomic == False. Enables Far Atomics on
systems where the HNF does not allocate evicted lines at LLC (Like in
WriteUpdate).