[WebAssembly] Make EH depend on multivalue and reference-types (#91299)

This PR turns on multivalue and reference-types features when
exception-handling feature is turned on, and errors out when disabling
of those dependent features is explicitly requested.

I think doing this would be safe anyway regardless of whether or when we
end up turning on reference-types by default.

We currently don't yet have a experimental flag for the Clang and LLVM
for the new experimental EH yet. But I think it should be fine to turn
those features on even if the LLVM does not yet generate the new EH
instructions, for the same reason we tried to turn them on by default
and the browsers that support EH also support multivalue and
reference-types anyway.