Add information about immediate and displacement operands to instr_t

_From [byron.c....@gmail.com](https://code.google.com/u/101184679827294438523/) on February 13, 2013 18:42:32_

I would like an easy way to identify the offset of any immediate and/or displacement operands within the instruction raw bits of an instr_t. Currently it would require replicating a significant part of the decoding process to find the offsets. So it would be ideal if this information could be added to instr_t during decoding.

This feature will benefit my research project, in which a data set is assembled from the instruction stream. We would like our data to be agnostic to arbitrary factors of PIC tables, load-time relocation, address randomization, etc. This requires filtering out the immediate and displacement operands. Currently my data collection code is truncating instructions to the opcode whenever any such operand is present. It would be much better for us if we could identify these operand bytes and filter them specifically.

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=1076_