compileopts, targets, main: support Wasmtime v14

[ydnar]

This PR adds support for Wasmtime v14 (released 2023-10-20), reenabling support for:

tinygo test -v -target=wasi ./...

1. Changes --mapdir=GUEST::HOST to --dir=HOST::GUEST
2. Reorders CLI arguments to wasmtime so Wasmtime arguments are before the .wasm module argument, and arguments to the Go program (e.g. -test.v) are after. The -- argument has no effect.

Note this PR does not attempt to detect the version of Wasmtime being run.

For additional context, see:

• Redesign Wasmtime's CLI bytecodealliance/wasmtime#6925
• Require Wasmtime options come before wasm modules bytecodealliance/wasmtime#6946

Fixes #3970.

[Mossaka]

lgtm!

[deadprogram]

The reason the CI tests are failing here, is because the change in this PR is not backward compatible with the old version (v5.0.0) of wasmtime being used for testing. For example, see https://github.com/tinygo-org/tinygo/blob/dev/.github/workflows/linux.yml#L143

So do we want to do one of these?

• drop support for older wasmtime versions
• try to detect the wasmtime version
• add a flag specifying the wamtime version, defaulting to either newest or older
• switch to wazero
• something else entirely

Thoughts?

[deadprogram]

In the meantime, how about #3976 to get our build back to green?

[ydnar]

@deadprogram thsnks! I'll rebase and pin this PR to v14.

Looks like Homebrew just updated to v14 yesterday: https://github.com/Homebrew/homebrew-core/blob/581c110863a917ada65b58cf046d93c2a2f6d105/Formula/w/wasmtime.rb

[ydnar]

@deadprogram rebased, now green.

[ydnar]

It appears that Wasmtime will issue a patch release with backwards compatibility: bytecodealliance/wasmtime#7336 (comment)

Most importantly, work is underway right now to put out a patch release that restores support for the current CLI (while retaining support for the new one as well).

We also agreed on handling the CLI as a stable interface with strong compatibility guarantees, as well as the shape of a process for ensuring that we can keep to these guarantees, as well as how we'll communicate changes to the CLI. We'll publish an RFC detailing this, with ample opportunity to weigh in.

Note that we deem the changes to the new interface foundationally important for these stability guarantees, so the RFC and an accompanying blog post will also include details on how we'll fully transition, and eventually sunset support for the old interface.

[ydnar]

Wasmtime v14.0.4 should be released this morning, which fixes known outstanding bugs with running tinygo: #3972

This PR adapts the old CLI to the new (v14+) CLI, so could probably be merged anytime before Wasmtime drops backwards compatibility.

[ydnar]

[email protected] is out: https://crates.io/crates/wasmtime-cli

[deadprogram]

Thanks for helping get this settled @ydnar now going to squash/merge