feat: SWC parser

[ottomated]

Very early look into using swc instead of acorn + acorn-typescript to parse (see #13439)

So far I've just implemented parse_expression_at, which was the main blocker keeping acorn necessary. 238 test failures right now, most due to error messages not being the same, some due to hacks put in place to appease acorn-typescript.

This is really just a proof-of-concept. Instead of using swc's estree compat layer, it would be better to use their AST representation (which has full types available at @swc/types and would be compatible with their print function to avoid a dependency on esrap).

To run:

• requires nightly Rust (rustup default nightly) - this is a requirement of swc_estree_compat which could be removed by using their AST as mentioned above
• requires wasm-pack
• requires cargo-watch (cargo install cargo-watch) for dev mode
• go to packages/swc-svelte and run pnpm dev to build the rust crate

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• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
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• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests and linting

• Run the tests with pnpm test and lint the project with pnpm lint

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[ottomated]

Note - SWC also exposes parse_pat, which could potentially replace read_pattern, thus rendering read_type_annotation unused and getting rid of some of the hacks

[trueadm]

Whilst this is super interesting, this isn't a route we plan on taking in the future. Given how stale and conflicted this PR is, I'm closing for now.

[ottomated]

@trueadm are there no longer plans to look into oxc once vite uses rolldown as mentioned in #13439?

[trueadm]

@ottomated oxc looks promising but its very early days there still, and the change in AST format would be a huge change for us, so likely something for the far future rather than the near future. The benefits we'd get would only start to be beneficial with Rolldown too, and that's not stable yet.