…01308)A PyThreadState can be in one of many states in its lifecycle, represented by some status value.  Those statuses haven't been particularly clear, so we're addressing that here.  Specifically:* made the distinct lifecycle statuses clear on PyThreadState* identified expectations of how various lifecycle-related functions relate to status* noted the various places where those expectations don't match the actual behaviorAt some point we'll need to address the mismatches.(This change also includes some cleanup.)python#59956