sema: add `prev` to ValueArena to allow freeing previous arenas when new ones are created during re-analysis
In semaDecl, it was possible for a new ArenaAllocators state to replace an existing one that
hadn't been freed yet. Instead of the ref_count (which was made redundant by adding
the allocator parameter to `release`), I now store a pointer to the previous arena, if one exists.
This allows a recursive deinit to happen when the last arena created is destroyed.
15dafd16e6kcbanner committed on 4/27/2023, 5:11:57 AMparent2b592d7