Add in support for LL/SC in the O3 CPU. Needs to be fully tested.

Add in support for LL/SC in the O3 CPU.  Needs to be fully tested.

src/cpu/base_dyn_inst.hh:
    Extend BaseDynInst a little bit so it can be use as a TC as well (specifically for ll/sc code).
src/cpu/base_dyn_inst_impl.hh:
    Add variable to track if the result of the instruction should be recorded.
src/cpu/o3/alpha/cpu_impl.hh:
    Clear lock flag upon hwrei.
src/cpu/o3/lsq_unit.hh:
    Use ISA specified handling of locked reads.
src/cpu/o3/lsq_unit_impl.hh:
    Use ISA specified handling of locked writes.

--HG--
extra : convert_revision : 1f5c789c35deb4b016573c02af4aab60d726c0e5