Add SENTINEL annotations for compare or test instructions in loops that don't use the last value of the induction var.

Increase memory annotations by tracing to the initial value for address regs on memory access instructions that have no annotations.

Compute loop follow nodes better; separate follow node errors from more serious unstructured CFG errors.

Try to get STARS/IRDB to imitate STARS/IDA more closely on static memory operand processing to help move_globals.