Blender Git Loki

Fix T73472: Crash in override code on dirty pose bone pointers.

Usual issue from those dear Bone pointers in pose data...

Note that this is more like minimal-risk, quick fix, it's nothing like
'nice to have' code. Think proper solution would be to refactor handling
of those kind of 'caches' to ensure they are valid/up-to-date in a much
easier way, at the very least.

Ideal solution being to get fully rid of those horrors, of course, but
let's not dream here. ;)