Have wizer enable `relaxed_simd_deterministic`, so that wizer's output
doesn't depend on the relaxed SIMD lowerings on the host that runs the
initialization code.

Strictly speaking, the Wasm spec [requires] relaxed SIMD instructions to
have the same behavior across all runs of a given program:

> These choices are fixed, that is, parameters are constant during the
execution of any given program.

[requires]: https://webassembly.github.io/spec/core/exec/numerics.html#relaxed-operations

Wizer doesn't have a way to ensure that this guarantee is upheld by
the engine the resumes execution after the snapshot in general. However,
by enabling deterministic lowerings for relaxed SIMD instructions, hosts
that chose to can also enable deterministic lowerings and match it.

Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>