This commit adds a bitfield to the iseq body that stores offsets inside the iseq buffer that contain values we need to mark. We can use this bitfield to mark objects instead of disassembling the instructions. This commit also groups inline storage entries and adds a counter for each entry. This allows us to iterate and mark each entry without disassembling instructions Since we have a bitfield and grouped inline caches, we can mark all VALUE objects associated with instructions without actually disassembling the instructions at mark time. [Feature #18875] [ruby-core:109042]