Run tests without wizening as well

Before testing that we get the expected result from the following sequence:

* initialize+snapshot with Wizer
* instantiate the snapshot
* call `run`

we should test that we get the expected result from the non-Wizer sequence:

* instantiate
* initialize
* call `run`

The `same_result` fuzz target does this, but the `run_wasm` helper in `tests/tests.rs` does not. It should.