…de the `AST` namespace from `"svelte/compiler"` (#15946)

* feat: State declarations in class constructors

* feat: Analysis phase

* misc

* feat: client

* improvements

* feat: It is now at least backwards compatible. though the new stuff may still be wrong

* feat: It works I think?

* final cleanup??

* tests

* test for better types

* changeset

* rename functions (the function doesn't test call-expression-ness)

* small readability tweak

* failing test

* fix

* disallow computed state fields

* tweak message to better accommodate the case in which state is declared after a regular property

* failing test

* wildly confusing to have so many things called 'class analysis' - rename the transform-phrase ones to transformers

* missed a spot

* and another

* store analysis for use during transformation

* move code to where it is used

* do the analysis upfront, it's way simpler

* skip failing test for now

* simplify

* get rid of the class

* on second thoughts

* reduce indirection

* make analysis available at transform time

* WIP

* WIP

* WIP

* fix

* remove unused stuff

* revert snapshot tests

* unused

* note to self

* fix

* unused

* unused

* remove some unused stuff

* unused

* lint, tidy up

* reuse helper

* tweak

* simplify/DRY

* unused

* tweak

* unused

* more

* tweak

* tweak

* fix proxying logic

* tweak

* tweak

* adjust message to accommodate more cases

* unskip and fix test

* fix

* move

* revert unneeded drive-by change

* fix

* fix

* update docs

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Co-authored-by: Rich Harris <rich.harris@vercel.com>

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>