fix: account for sourcemap in meta info

[dummdidumm]

We need to use a different method for getting the meta info because locate is used to help construct the source map that references the preprocessed Svelte file. If we would now add source maps to that locate function it would go the the original source directly which means skipping potentially intermediate source maps which we would need in other situations.

Also adds a new dependency, cc @benmccann that might affect the blog post

fixes #8360
closes #8362

TODO:

• think one more time if there really isn't a way to reuse the other stuff (didn't find a better way)
• needs to also convert the character (update: limitation we can't solve, noted in a TODO)
• tests

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[benmccann]

it's confusing to me that we used a 1-based locator for meta_locate and then subtract 1. if we just used the default sourcemap offset we wouldn't have to deal with that

we could make meta_locate use a separate 0-based locator. would that be more expensive though?

or we could make locate be 0-based and then just add 1 when we're printing it out. I think that'd be clearer because sourcemaps are 0-based and then we can just treat everything in the codebase as being 0-based. is locate exposed externally though and would that be a breaking change that results in a more difficult API for people needing to print stack traces?

[dummdidumm]

This won't change much as the source mapping function works on 1-based lines so we have back and forth either way. I think the way it's now is the most consistent (both locate and meta_locate are 1-based) and you do whatever you need to do on the consumer side (and 1-based is needed more often)

[benmccann]

Also adds a new dependency, cc @benmccann that might affect the blog post

It looks like @jridgewell/trace-mapping was already a transitive dependency, so this doesn't change much

[dummdidumm]

Ah nice 👍

[dominikg]

Nice, I think this solves my concern about internal state in the locator as well. I don't really like having both 0 and 1 index things going on but it is what it is.

[benmccann]

Nice, I think this solves my concern about internal state in the locator as well. I don't really like having both 0 and 1 index things going on but it is what it is.

Also, locate-character has been updated to the latest version where I think that issue was fixed