plugin updates (register access) for 9.0 (pre-PR?) Akihiko requested the register support not be merged in its current state so it's time for another round of review. I've made a few tweaks to simplify the register and CPU tracking code in execlog and removed some stale API functions. However from my point of view its ready to merge. v3 -- - split from testing bits (merged) - removed unused api funcs - keep CPUs in a GArray instead of doing by hand v2 -- - Review feedback for register API - readthedocs update - add expectation docs for plugins The following still need review: contrib/plugins: extend execlog to track register changes gdbstub: expose api to find registers