[RFC] Support LLVM_LINK_LLVM_DYLIB on MSVC (90% size reduction)

I’ve always felt we should bite the bullet and make this transition (see last year’s RFC, although Windows was out of scope). We could make it part of CI, and that would keep the annotations up to date. I’m sure people will find it annoying, but it’s worth the development pain for the value it will create for users.

I’ve never had a business reason to really champion this direction, though, so I’ve continuously been in this useless space of saying “this is the solution”, without actually doing the legwork. Apologies for the inconsistency.