Memcpy optimization for stream<T>/future<T> shouldn't apply to `bool` or `char`

According to https://github.com/WebAssembly/component-model/pull/584 these types are `memcpy`'d, but `char` needs validation and `bool` I believe is canonicalized to 0/1.