Currently when calling wasm_runtime_call_wasm() to invoke wasm function
with externref type argument from runtime embedder, developer needs to
use wasm_externref_obj2ref() to convert externref obj into an internal ref
index firstly, which is not convenient to developer.
To align with GC feature in which all the references passed to
wasm_runtime_call_wasm() can be object pointers directly, we change the
interface of wasm_runtime_call_wasm() to allow to pass object pointer
directly for the externref argument, and refactor the related codes, update
the related samples and the document.
The WASM C API now requires the use of vector types in certain apis.
Switching WAMR to use the new call signatures improves "drop in"
compilation compatibility between WAMR and other implementations
from a C-api embedding program's perspective.
* wasm_func_callback_t type has been updated to use wasm_val_vec_t
* wasm_func_callback_with_env_t type has been updated to use wasm_val_vec_t
* wasm_func_call() has been updated to use wasm_val_vec_t
* wasm_instance_new() has been updated to use wasm_extern_vec_t*
* wasm_instance_new_with_args() has been updated to use wasm_extern_vec_t*
* wasm_runtime_invoke_c_api_native() has been updated to support vector types
in native callbacks without modifying the contract with the interpreter code.
* All users of the modified functions (including samples/wasm-c-api/src/*.c)
have been appropriately updated.