This bring unwind and personality code more in line with strict-provenance

On native builds `llvm-config` picks up `zlib` and this gets pased into
the rust build tools, but on cross builds `llvm-config` is explicitly
ignored as it contains information for the host system and cannot be
trusted to be accurate for the target system.

Both DragonFly and Solaris contain `zlib` in the base system, so this is
both a safe assumption and required for a successful cross build unless
`zlib` support is disabled in LLVM.

This is more or less in the same vein as rust-lang#75713 and rust-lang#75655.

* Entries in the callsite table now use a dedicated function for reading an offset rather than a pointer
* `read_encoded_pointer` uses that new function for reading offsets when the "application" part of the encoding indicates an offset (relative to some pointer)
* It now errors out on nonsensical "application" and "value encoding" combinations

Inspired by @eddyb's comment on zulip about this:
<https://rust-lang.zulipchat.com/#narrow/stream/136281-t-opsem/topic/strict.20provenance.20in.20dwarf.3A.3Aeh/near/276197290>

As far as I know, this is always true already, but it's not in the text of the Option module docs, so I figured I'd bring this up to FCP it.

…olid::is_interrupted`

…-libz, r=cuviper

rustc_llvm: Link to `zlib` on dragonfly and solaris

On native builds `llvm-config` picks up `zlib` and this gets pased into
the rust build tools, but on cross builds `llvm-config` is explicitly
ignored as it contains information for the host system and cannot be
trusted to be accurate for the target system.

Both DragonFly and Solaris contain `zlib` in the base system, so this is
both a safe assumption and required for a successful cross build unless
`zlib` support is disabled in LLVM.

This is more or less in the same vein as rust-lang#75713 and rust-lang#75655.

Strict provenance unwind

1. Turned many `usize`s in the personality/unwind code that are actually pointers into `*const u8`.
2. Rewrote `read_encoded_pointer` to conform to strict-provenance, along the lines as described by `@eddyb` [in zulip some time ago](https://rust-lang.zulipchat.com/#narrow/stream/136281-t-opsem/topic/strict.20provenance.20in.20dwarf.3A.3Aeh/near/276197290).

This should make supporting CHERI in the future easier (but they use a [slightly modified format in the callsite table](https://cheri-compiler-explorer.cl.cam.ac.uk/z/n6GhhW), which requires a CHERI specific modification to `find_eh_action`).

Add alignment to the NPO guarantee

This PR [changes](rust-lang#114845 (comment)) "same size" to "same size and alignment" in the option module's null pointer optimization docs in <https://doc.rust-lang.org/std/option/#representation>.

As far as I know, this has been true for a long time in the actual rustc implementation, but it's not in the text of those docs, so I figured I'd bring this up to FCP it.

I also see no particular reason that we'd ever *want* to have higher alignment on these.  In many of the cases it's impossible, as the minimum alignment is already the size of the type, but even if we *could* do things like on 32-bit we could say that `NonZeroU64` is 4-align but `Option<NonZeroU64>` is 8-align, I just don't see any value in doing that, so feel completely fine closing this door for the few things on which the NPO is already guaranteed.  These are basically all primitives, and should end up with the same size & alignment as those primitives.

(There's no layout guarantee for something like `Option<[u8; 3]>`, where it'd be at least plausible to consider raising the alignment from 1 to 4 on, say, some hypothetical target that doesn't have efficient unaligned 4-byte load/stores.  And even if we ever did start to offer some kind of guarantee around such a type, I doubt we'd put it under the "null pointer" optimization header.)

Screenshots for the new examples:
![image](https://github.com/rust-lang/rust/assets/18526288/a7dbff42-50b4-462e-9e27-00d511b58763)
![image](https://github.com/rust-lang/rust/assets/18526288/dfd55288-80fb-419a-bc11-26198c27f9f9)

Use `OnceLock` for `SingleCache`

This uses `OnceLock` for `SingleCache` instead of `Lock<Option<T>>` so lookups are lock-free.

r? `@cjgillot`

…upted, r=cuviper

kmc-solid: Fix `is_interrupted`

Follow-up to rust-lang#115228. Fixes a build error in [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets.

```
error[E0603]: function `is_interrupted` is private
  --> library\std\src\sys\solid\mod.rs:77:12
   |
77 |     error::is_interrupted(code)
   |            ^^^^^^^^^^^^^^ private function
   |
note: the function `is_interrupted` is defined here
  --> library\std\src\sys\solid\error.rs:35:1
   |
35 | fn is_interrupted(er: abi::ER) -> bool {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```

…rough, r=cjgillot

Fall through when resolving elided assoc const lifetimes

`@QuineDot` makes a good point in rust-lang#115010 (comment) that we probably should not accept *more* code due to rust-lang#115011 even though that code will eventually become a forbid-warning in a few versions (rust-lang#115010 (comment)).

Fall through when walking thru the `AnonymousWarnToStatic` (renamed to `AnonymousWarn`) rib so that we can resolve as a fresh lifetime like we did before.

…ChrisDenton

Const-stabilize `is_ascii`

Resolves rust-lang#111090

FCP completed in rust-lang#111090 (comment)

…spastorino

Add spastorino on vacation