wasi: relax WebAssembly.Instance type check

Instances coming from different VM contexts don't pass `instanceof`
type checks because each context has its own copy of the built-in
globals.

After review of the relevant code it seems like it should be safe to
relax the type check and that is what this commit does: `wasi.start()`
now accepts any input that walks and quacks like a WebAssembly.Instance
or WebAssembly.Memory instance.

Fixes: https://github.com/nodejs/node/issues/33415

PR-URL: https://github.com/nodejs/node/pull/33431


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>