Fix corner case on assertion.

Fix corner case on assertion.
I need to move over to using the fixPacket function so I don't have to make the same changes everywhere.
Still a functional access bug someplace I need to track down in timing mode.

src/mem/cache/base_cache.cc:
src/mem/cache/cache_impl.hh:
    Fix corner case on assertion
tests/configs/memtest.py:
    Updated memtester with uncacheable addresses and functional accesses

--HG--
extra : convert_revision : e6fa851621700ff9227b83cc5cac20af4fc8444f