- Add method to easily create local for virtual stack
- Ensure function pointers are passed correctly
- Correctly handle slices as return types and values
- Fix wrapping error sets/payloads.
- Handle ptr-like optionals correctly, by using address '0' as null.
- Implement `array_to_slice`
- linker: Always emit a table, so call_indirect inside bodies do not fail if there's no table.
TODO: Only do this when we emit a call_indirect but the relocation cannot be resolved.