Allow struct.wait on equality-comparable fields except floats (#8939)

Part of #8315. #8672 added struct.wait for i32 struct fields, but left
out support for i64 and subtypes of `ref null (shared eq)`. See the
details in the
[proposal](https://github.com/WebAssembly/shared-everything-threads/blob/main/proposals/shared-everything-threads/Overview.md#managed-waiter-queues).