Add memory instance support apis

[bnason-nf]

Now that WAMR supports multiple memory instances, this adds some APIs to access them in a standard way.

This involved moving some existing utility functions out from the WASM_ENABLE_MULTI_MODULE blocks they were nested in, but multi-memory and multi-module seem independent as far as I can tell so I assume that's okay.

[lum1n0us]

Just my thoughts, it seems that functions(and code) related to exporting should not be limited by the WASM_ENABLE_MULTI_MODULE.

[wenyongh]

Could we add argument module for wasm_memory_inst_enlarge and here pass it to wasm_enlarge_memory_internal? Since module may be used in wasm_enlarge_memory_internal, and developer should know it when calling wasm_memory_inst_enlarge.

bool
wasm_memory_inst_enlarge(WASMModuleInstanceCommon *module_inst,
                         WASMMemoryInstance *memory, uint64 inc_page_count)
{
    ...
    wasm_enlarge_memory_internal(module_inst, memory, ..);
    ...
}

[bnason-nf]

@wenyongh in order to support externally created (imported) memory objects, you have to be able to create them independent of a module or module instance, so I think we should leave this API without a required module argument. However, I'm OK with adding a module argument and making it optional.

[wenyongh]

If we add argument module to wasm_memory_inst_enlarge and passing argument module to wasm_enlarge_memory_internal, then here we don't add the check && module.

[bnason-nf]

This relates to the previous comments, if we added a module argument to wasm_memory_inst_enlarge(), I think it should be optional. If so, we would still need to check it here.

[wenyongh]

OK, got it.

[wenyongh]

There is already a function bool wasm_runtime_enlarge_memory(module_inst, inc_page_count) but it enlarge the default memory. Do you think it is better to use wasm_runtime_enlarge_memory_with_idx?

[bnason-nf]

This relates to previous comments:

#3786 (comment)
#3786 (comment)

For memories created independently of a module or module instance, providing an index has no meaning, so I think this API should remain like this.

[wenyongh]

LGTM