Warn against calls which mutate an interior mutable const-item

[Urgau]

const_item_interior_mutations

interior_mutable_const_item_mutations

suspicious_mutation_of_interior_mutable_consts

warn-by-default

The const_item_interior_mutations lint checks for calls which mutates an interior mutable const-item.

Example

use std::sync::Once;

const INIT: Once = Once::new(); // using `INIT` will always create a temporary and
                                // never modify it-self on use, should be a `static`
                                // instead for shared use

fn init() {
    INIT.call_once(|| {
        println!("Once::call_once first call");
    });
}

warning: mutation of an interior mutable `const` item with call to `call_once`
  --> a.rs:11:5
   |
11 |       INIT.call_once(|| {
   |       ^---
   |       |
   |  _____`INIT` is a interior mutable `const` item of type `std::sync::Once`
   | |
12 | |         println!("Once::call_once first call");
13 | |     });
   | |______^
   |
   = note: each usage of a `const` item creates a new temporary
   = note: only the temporaries and never the original `const INIT` will be modified
   = help: for more details on interior mutability see <https://doc.rust-lang.org/reference/interior-mutability.html>
   = note: `#[warn(const_item_interior_mutations)]` on by default
help: for a shared instance of `INIT`, consider making it a `static` item instead
   |
 6 - const INIT: Once = Once::new(); // using `INIT` will always create a temporary and
 6 + static INIT: Once = Once::new(); // using `INIT` will always create a temporary and
   |

Explanation

Calling a method which mutates an interior mutable type has no effect as const-item are essentially inlined wherever they are used, meaning that they are copied directly into the relevant context when used rendering modification through interior mutability ineffective across usage of that const-item.

The current implementation of this lint only warns on significant std and core interior mutable types, like Once, AtomicI32, ... this is done out of prudence and may be extended in the future.

---

This PR is an targeted alternative to #132146. It avoids false-positives by adding an internal-only attribute #[rustc_should_not_be_called_on_const_items] on methods and functions that mutates an interior mutale type through a shared reference (mutable refrences are already linted by the const_item_mutation lint).

It should also be noted that this is NOT an uplift of the more general clippy::borrow_interior_mutable_const lint, which is a much more general lint regarding borrow of interior mutable types, but has false-positives that are completly avoided by this lint.

A simple GitHub Search reveals many instance where the user probably wanted to use a static-item instead.

---

@rustbot labels +I-lang-nominated +T-lang
cc @traviscross
r? compiler

Fixes IRLO - Forbidding creation of constant mutexes, etc
Fixes #132028
Fixes #40543