Rollup merge of #123480 - Nadrieril:impl-all-derefpures, r=compiler-errors

deref patterns: impl `DerefPure` for more std types

Context: [deref patterns](https://github.com/rust-lang/rust/issues/87121). The requirements of `DerefPure` aren't precise yet, but these types unambiguously satisfy them.

Interestingly, a hypothetical `impl DerefMut for Cow` that does a `Clone` would *not* be eligible for `DerefPure` if we allow mixing deref patterns with normal patterns. If the following is exhaustive then the `DerefMut` would cause UB:
```rust
match &mut Cow::Borrowed(&()) {
    Cow::Owned(_) => ..., // Doesn't match
    deref!(_x) if false => ..., // Causes the variant to switch to `Owned`
    Cow::Borrowed(_) => ..., // Doesn't match
    // We reach unreachable
}
```

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