util:  update aggregator to handle x86 checkpoints. Also, make update to understand some of the newer serialized variables
util:  update aggregator to handle x86 checkpoints.
Also, make update to understand some of the newer serialized variables

andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin