Implement Typed IR

[Derppening]

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[Derppening]

Most of the work should be done now. I will go through the changes once more tomorrow and clean this up.

[Derppening]

For some reason I can't reproduce the diff in the CI locally...

-//│       set tmp = Runtime⁰.Tuple¹.get¹(c, 1);
+//│       set tmp = Runtime⁰.Tuple⁰.get⁰(c, 1);

[Derppening]

Dropped e95e681 and merged LPTK#27 into this branch to fix the Prelude.mls cache issue.

[Derppening]

Pushed two more fixes:

• Added support for curried functions in ErasedType.FuncRef

  Partially-applied curried functions used to incorrectly collapse to the type of the return value rather than a FuncRef with the applied parameter lists dropped from its signature.

• Fixed a mismatch between the representation of Object in the erased type system and the backends

  ErasedType.Object represents the top-reference type (which includes types like Int), whereas Object in JS/Wasm represents globalThis.Object and the $Object base class, which notably exclude Number (in JS) and i31ref (in Wasm)

I will go through the whole diff tomorrow (especially the new difftests) to try to unslopify some of the changes and simplify the verbose explanations Claude likes to attach to its work. I will mark this ready-for-review once this is done.

Edit: Depends on LPTK#27.