BrTable is currently the only Operator member that requires dynamic allocation. It's desirable to avoid dynamic allocation during decoding in general, and eliminating this instance of it would eliminate the need for drop calls in the compiled code for Operator.

One way to do this would be to have BrTable hold an iterator, which then decodes the table contents on demand, instead of copying them into a Vec. A possible variant of this would be to make it return a slice of the input buffer, which could then be decoded on demand.