Auto merge of #124661 - RalfJung:only-structural-consts-in-patterns, r=pnkfelix

Turn remaining non-structural-const-in-pattern lints into hard errors

This completes the implementation of rust-lang/rust#120362 by turning our remaining future-compat lints into hard errors: indirect_structural_match and pointer_structural_match.

They have been future-compat lints for a while (indirect_structural_match for many years, pointer_structural_match since Rust 1.75 (released Dec 28, 2023)), and have shown up in dependency breakage reports since Rust 1.78 (just released on May 2, 2024). I don't expect a lot of code will still depend on them, but we will of course do a crater run.

A lot of cleanup is now possible in const_to_pat, but that is deferred to a later PR.

Fixes rust-lang/rust#70861

Author: bors