- Restrict const-anon exception diag to relevant places
 - Invoke bounds (and type-inference) in non_local_defs
 - Specialize diagnostic for impl without Trait

 - Remove wrong exception text for non-local macro_rules!
 - Simplify anonymous const exception note

…=estebank

Improve diagnostic output the `non_local_definitions` lint

This PR improves (or at least tries to improve) the diagnostic output the `non_local_definitions` lint, by simplifying the wording, by adding a "sort of" explanation of bounds interaction that leak the impl...

This PR is best reviewed commit by commit and is voluntarily made a bit vague as to have a starting point to improve on.

Related to https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/non_local_defs.20wording.20improvements

Fixes rust-lang#125068
Fixes rust-lang#124396
cc `@workingjubilee`
r? `@estebank`

…, r=compiler-errors

`-Znext-solver`: eagerly normalize when adding goals

fixes rust-lang#125269. I am not totally with this fix and going to keep this open until we have a more general discussion about how to handle hangs caused by lazy norm in the new solver.

Stabilise `IpvNAddr::{BITS, to_bits, from_bits}` (`ip_bits`)

This completed FCP in rust-lang#113744. (Closes rust-lang#113744.)

Stabilises the following APIs:

```rust
impl Ipv4Addr {
    pub const BITS: u32 = 32;
    pub const fn from_bits(bits: u32) -> Ipv4Addr;
    pub const fn to_bits(self) -> u32;
}

impl Ipv6Addr {
    pub const BITS: u32 = 128;
    pub const fn from_bits(bits: u128) -> Ipv4Addr;
    pub const fn to_bits(self) -> u128;
}
```

…, r=lcnr

Make `ProofTreeBuilder` actually generic over `Interner`

Self-explanatory. Also renamed `ecx.tcx()` to `ecx.interner()`.

r? lcnr