Support for Serializable non-SimObject things like events.

Support for Serializable non-SimObject things like events.
Can now serialize & unserialize DmaRequestEvents and DmaTransferEvents.
Also support serialize/unserialize of pointers to SimObjects and
other Serializable objects.

arch/alpha/alpha_memory.cc:
arch/alpha/alpha_memory.hh:
arch/alpha/isa_traits.hh:
cpu/exec_context.cc:
cpu/exec_context.hh:
cpu/simple_cpu/simple_cpu.hh:
dev/alpha_access.h:
dev/alpha_console.cc:
dev/alpha_console.hh:
dev/console.cc:
dev/console.hh:
    unserialize() now takes a Checkpoint* instead of an IniFile*.
cpu/simple_cpu/simple_cpu.cc:
    unserialize() now takes a Checkpoint* instead of an IniFile*.
    Put ExecContext in its own section so its _status fields doesn't conflict.
sim/eventq.cc:
sim/eventq.hh:
    unserialize() now takes a Checkpoint* instead of an IniFile*.
    Events get serialized by the event queue only if they're marked
    as AutoSerialize... others are assumed to be serialized by something
    else (e.g. an owning SimObject) or to not matter.
sim/param.cc:
    Shift 'const' in case T is a ptr type.
sim/serialize.cc:
sim/serialize.hh:
    Define Checkpoint object to encapsulate everything you need to know
    about a checkpoint.  Use it to allow lookups of named Serializable
    objects (and SimObjects) during unserialization.
    unserialize() now takes a Checkpoint* instead of an IniFile*.

--HG--
extra : convert_revision : 8e6baab32405f8f548bb67a097b2f713296537a5