Function wasm_extern_as_func 

#[unsafe(no_mangle)]
pub extern "C" fn wasm_extern_as_func(
    e: &mut wasm_extern_t,
) -> Option<&mut wasm_func_t>

Returns the wasm_extern_t as reference to mutable wasm_func_t if possible.

Returns None if e is not a wasm_func_t.