Remove --enable-gc from help text

[soegaard]

According to issue #2530 the GC proposal is not supported by wat2asm. Having --enable-gc in the help text gives a false impression.

[sbc100]

I looks like you are just updating the test expectation.

I think you would also need to update the wat2wasm source code itself.

[soegaard]

Oh! I didn't look closely enough. I thought, that was the help text printed by the tool wat2wasm.
Looking at the code, the option --enable-gc is added here:

https://github.com/WebAssembly/wabt/blob/main/include/wabt/feature.def#L38

But - and it is a big but - the options are shared between the tools,
so if other tools support GC then we can't remove it from the feature.def.

What would be the least intrusive way of handling this?
A simple idea: make wat2wasm print a note after the examples in:

https://github.com/WebAssembly/wabt/blob/main/src/tools/wat2wasm.cc#L51

The note could simply say that the --enable-gc option has no effect.

Not ideal, but at least low effort.

[sbc100]

How about just renaming it to --enable-gc-experimental?

[soegaard]

How about just renaming it to --enable-gc-experimental?

I would interpret a flag --enable-gc-experimental as "GC is implemented, but it is still a WIP".
Or perhaps that the specification might change.
My understanding is that --enable-gc is a noop for wat2wasm.

From the perspective of a user new to Wasm that just wants to try out Wasm:
he sees i31 in the GC spec. Checks the help of wat2wasm and sees he must
use --enable-gc to use the GC proposal. To his surprise none of the example programs works.

Adding a line in the README would help.
Removing the flag from the help text of wat2wasm even better.

I'll close this PR (since the fix was wrong) and create an issue instead.