Created by: egrimley
A check_reachable member is added to the previously unused decode_info_t struct and the encoder functions acquire an extra argument which is a pointer to this struct. The functions that encode branches, ADR and ADRP refer to this and accept unreachable targets when check_reachable is false, setting the offset to zero in this case. Targets are still required to be aligned.
Fixes #2681 (closed)
Change-Id: I4575a396bf13ee9fd27e395b10957eed294342ce