Various cleanup. Mostly forcing initialization of some fields...

Various cleanup.  Mostly forcing initialization of some fields...
I noticed that checkpoints dumped from m5.debug and m5.opt had
differences, which is no longer the case (other than addresses
encoded in names).

cpu/full_cpu/smt.hh:
    Get rid of unused SMT_MAX_CPUS.
sim/debug.cc:
    Use AutoDelete for DebugBreakEvent.
sim/serialize.cc:
sim/serialize.hh:
    Move constructor & destructor to header so they can be inlined.

--HG--
extra : convert_revision : bc68c2c9b053b1de0d655ed555734419fafd0b83