Switch to `EarlyBinder` for `thir_abstract_const` query Part of the work to finish https://github.com/rust-lang/rust/issues/105779. This PR adds `EarlyBinder` to the return type of the `thir_abstract_const` query and removes `bound_abstract_const`. r? `@compiler-errors`
For more information about how rustc works, see the rustc dev guide.