message: fix(c-api) Ensure that uninitialized boxed vec are zeroed.
  This patch updates how `wasm_$name_vec_new_uninitialized` creates the
  vector. The vector is now fully allocated with `null` pointer for each
  item, instead of having an empty vector with the initial capacity set
  to `length`. That way, we are sure the vector is zeroed correctly.
diff: @@ -326,7 +326,7 @@ int main() {
  ```"]
  #[no_mangle]
  pub unsafe extern "C" fn [<wasm_ $name _vec_new_uninitialized>](out: *mut [<wasm_ $name _vec_t>], length: usize) {
  - let mut bytes: Vec<*mut [<wasm_ $name _t>]> = Vec::with_capacity(length);
  + let mut bytes: Vec<*mut [<wasm_ $name _t>]> = vec![::std::ptr::null_mut(); length];
  let pointer = bytes.as_mut_ptr();
  (*out).data = pointer;
  