Add bulk memory operations

[patrickgwsmith]

https://github.com/WebAssembly/bulk-memory-operations/blob/master/proposals/bulk-memory-operations/Overview.md

LLM generated summary:

The Bulk Memory Operations proposal includes:

• memory.init: Initializes a range of memory with data from a data segment.
• data.drop: Drops a data segment so it can no longer be used.
• memory.copy: Copies data from one region of memory to another.
• memory.fill: Fills a region of memory with a specified byte value.

Bulk Memory Operations Instructions

1. memory.init
   • Used to initialize a memory region with data from a data segment.
   • Signature: memory.init .
   • Example: memory.init 0 0.
2. data.drop
   • Marks a data segment as no longer needed.
   • Signature: data.drop .
   • Example: data.drop 0.
3. memory.copy
   • Copies data from one memory region to another.
   • Signature: memory.copy .
   • Example: memory.copy 10 0 5.
4. memory.fill
   • Fills a memory region with a specified byte value.
   • Signature: memory.fill .
   • Example: memory.fill 0 255 10.