The Fail* tools expect trace events to be ordered in a specific way:
memory-access events are supposed to come *after* the instruction
event for the instruction that caused them. Using a different order
may cause subtle problems with both fault-space pruning and fast
forwarding. This change introduces a warning message when such a
malformed trace is detected (i.e., when the instruction pointer of a
memory-access event does not match the preceding instruction event).
Change-Id: I8ae7420fd8ff26e2574590748bdcc5a63db76490