Split SimpleCPU into two different models, AtomicSimpleCPU and

Split SimpleCPU into two different models, AtomicSimpleCPU and
TimingSimpleCPU, which use atomic and timing memory accesses
respectively.  Common code is factored into the BaseSimpleCPU class.
AtomicSimpleCPU includes an option (simulate_stalls) to add delays
based on the estimated latency reported by the atomic accesses.
Plain old "SimpleCPU" is gone; I have not updated all the config
files (just test/test.py).
Also fixes to get timing accesses working in new memory model and
to get split-phase memory instruction definitions working with
new memory model as well.

arch/alpha/isa/main.isa:
    Need to include packet_impl.h for functions that use Packet objects.
arch/alpha/isa/mem.isa:
    Change completeAcc() methods to take Packet object pointers.
    Also split out StoreCond template for completeAcc(), since
    that's the only one that needs write_result and we get an
    unused variable warning if we always have it in there.
build/SConstruct:
    Update list of recognized CPU model names.
configs/test/test.py:
    Change SimpleCPU to AtomicSimpleCPU.
cpu/SConscript:
    Define sources for new CPU models.
    Add split memory access methods to CPU model signatures.
cpu/cpu_models.py:
cpu/static_inst.hh:
    Define new CPU models.
cpu/simple/base.cc:
cpu/simple/base.hh:
    Factor out pieces specific to Atomic or Timing models.
mem/bus.cc:
    Bus needs to be able to route timing packets based on explicit dest
    so responses can get back to requester.  Set dest to Packet::Broadcast
    to indicate that dest should be derived from address.
    Also set packet src field based on port from which packet is sent.
mem/bus.hh:
    Set packet src field based on port from which packet is sent.
mem/packet.hh:
    Define Broadcast destination address to indicate that
    packet should be routed based on address.
mem/physical.cc:
    Set packet dest on response so packet is routed
    back to requester properly.
mem/port.cc:
    Flag blob packets as Broadcast.
python/m5/objects/PhysicalMemory.py:
    Change default latency to be 1 cycle.

--HG--
rename : cpu/simple/cpu.cc => cpu/simple/base.cc
rename : cpu/simple/cpu.hh => cpu/simple/base.hh
extra : convert_revision : e9646af6406a20c8c605087936dc4683375c2132