* Update differential fuzzing configuration
This uses some new features of `wasm-smith` and additionally tweaks the
existing fuzz configuration:
* More than one function is now allowed to be generated. There's no
particular reason to limit differential execution to just one and we
may want to explore other interesting module shapes.
* More than one function type is now allowed to possibly allow more
interesting `block` types.
* Memories are now allowed to grow beyond one page, but still say small
by staying underneath 10 pages.
* Tables are now always limited in their growth to ensure consistent
behavior across engines (e.g. with the pooling allocator vs v8).
* The `export_everything` feature is used instead of specifying a
min/max number of exports.
The `wasmi` differential fuzzer was updated to still work if memory is
exported, but otherwise the v8 differential fuzzer already worked if a
function was exported but a memory wasn't. Both fuzzers continue to
execute only the first exported function.
Also notable from this update is that the `SwarmConfig` from
`wasm-smith` will now include an arbitrary `allowed_instructions`
configuration which may help explore the space of interesting modules
more effectively.
* Fix typos
52ad76ed7c