Additional GC Support

[thesuhas]

Currently, Orca has basic GC support where it can capture and reencode any GC-specific instructions in the .wasm and only has APIs for instruction injection. It does not support other types of instrumentation that is related to GC.

Ways to extend this would be:

• Ability to add Struct Types
• Ability to add Array Types
• All type-addition APIs would be extended to have supertype, shared, and is_final.

Additionally, currently we store a mapping from func type index to rec group index to encode the recgroup. We would need to maintain a mapping of old type -> new type. This is necessary when the user adds/removes types and the recgroup mapping may not be consistent.