Define a `NotHandle` type, that implements `std::error::Error`, and use
it as the error type in `HandleOrNull` and `HandleOrInvalid`.

Also, make the display messages more specific, and remove the `Copy`
implementation.

I managed to break this in rust-lang#95449.
I am not quite sure why this is the correct fix, but it doesn't break `doc --stage 0`
and is strictly closer to the previous behavior.

Previously, rustdoc would error with strange issues because of the mismatched sysroot:
```
error[E0460]: found possibly newer version of crate `std` which `rustc_span` depends on
  --> /home/jnelson/rust-lang/rust/compiler/rustc_lint_defs/src/lib.rs:14:5
   |
14 | use rustc_span::{sym, symbol::Ident, Span, Symbol};
   |     ^^^^^^^^^^
   |
   = note: perhaps that crate needs to be recompiled?
   = note: the following crate versions were found:
           crate `std`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-ff9290e971253a38.rlib
           crate `std`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-ff9290e971253a38.so
           crate `rustc_span`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_span-ed11dce30c1766f9.rlib
```

Removes the use `rustc_layout_scalar_valid_range_start` and some `unsafe` blocks.

… extra level of struct nesting.

…um, r=davidtwco

Stabilize `derive_default_enum`

This stabilizes `#![feature(derive_default_enum)]`, as proposed in [RFC 3107](rust-lang/rfcs#3107) and tracked in rust-lang#87517. In short, it permits you to `#[derive(Default)]` on `enum`s, indicating what the default should be by placing a `#[default]` attribute on the desired variant (which must be a unit variant in the interest of forward compatibility).

`@rustbot` label +S-waiting-on-review +T-lang

…rror-type, r=joshtriplett

Define a dedicated error type for `HandleOrNull` and `HandleOrInvalid`.

Define a `NotHandle` type, that implements `std::error::Error`, and use
it as the error type in `HandleOrNull` and `HandleOrInvalid`.

This addresses [this concern](rust-lang#87074 (comment)).

r? `@joshtriplett`

…Simulacrum

Fix `x test --doc --stage 0 library/std`

I managed to break this in rust-lang#95449.
I am not quite sure why this is the correct fix, but it doesn't break `doc --stage 0`
and is strictly closer to the previous behavior.

Previously, rustdoc would error with strange issues because of the mismatched sysroot:
```
error[E0460]: found possibly newer version of crate `std` which `rustc_span` depends on
  --> /home/jnelson/rust-lang/rust/compiler/rustc_lint_defs/src/lib.rs:14:5
   |
14 | use rustc_span::{sym, symbol::Ident, Span, Symbol};
   |     ^^^^^^^^^^
   |
   = note: perhaps that crate needs to be recompiled?
   = note: the following crate versions were found:
           crate `std`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-ff9290e971253a38.rlib
           crate `std`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-ff9290e971253a38.so
           crate `rustc_span`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_span-ed11dce30c1766f9.rlib
```

… r=m-ou-se

Implement `core::ptr::Unique` on top of `NonNull`

Removes the use `rustc_layout_scalar_valid_range_start` and some `unsafe` blocks.

…ylan-DPC

couple of clippy::complexity fixes

Update cargo

11 commits in e2e2dddebe66dfc1403a312653557e332445308b..dba5baf4345858c591517b24801902a062c399f8
2022-04-05 17:04:53 +0000 to 2022-04-13 21:58:27 +0000
- Part 6 of RFC2906 - Switch the inheritance source from `workspace` to… (rust-lang/cargo#10564)
- Part 5 of RFC2906 - Add support for inheriting `rust-version` (rust-lang/cargo#10563)
- Add support for rustc --check-cfg well known names and values (rust-lang/cargo#10486)
- Reserve filename `Cargo.toml.orig` in `cargo package` (rust-lang/cargo#10551)
- Retry command invocation with argfile (rust-lang/cargo#10546)
- Add a progress indicator for `cargo clean` (rust-lang/cargo#10236)
- Ensure host units don't depend on Docscrape units, fixes rust-lang/cargo#10545 (rust-lang/cargo#10549)
- Fix docs: Bindeps env vars are passed to build script at runtime (rust-lang/cargo#10550)
- Part 4 of RFC2906 - Add support for inheriting `readme` (rust-lang/cargo#10548)
- Part 3 of RFC2906 - Add support for inheriting `license-path`, and `depednency.path` (rust-lang/cargo#10538)
- Bump to 0.63.0, update changelog (rust-lang/cargo#10544)

Update books

## nomicon

1 commits in 11f1165e8a2f5840467e748c8108dc53c948ee9a..c7d8467ca9158da58ef295ae65dbf00a308752d9
2022-03-19 16:02:00 -0400 to 2022-04-06 14:26:54 +0900
- Change "writers" to "readers" for Deref. (rust-lang/nomicon#346)

## reference

7 commits in c97d14fa6fed0baa9255432b8a93cb70614f80e3..b5f6c2362baf932db9440fbfcb509b309237ee85
2022-03-19 18:18:10 -0700 to 2022-04-10 19:19:51 -0700
- Fix typo: `?` should be inside `<sup>` tags (rust-lang/reference#1190)
- Update aarch64 to use neon as fp (rust-lang/reference#1184)
- Boolean literal expressions (rust-lang/reference#1189)
- Document that unary negation of a signed integer literal cannot cause an overflow error (rust-lang/reference#1188)
- Document compatibility between declarative and procedural macro tokens (rust-lang/reference#1169)
- Document native library modifier syntax and the `whole-archive` modifier specifically (rust-lang/reference#1170)
- Numeric literal expressions and literal suffixes (rust-lang/reference#1177)

## book

8 commits in ea90bbaf53ba64ef4e2da9ac2352b298aec6bec8..765318b844569a642ceef7bf1adab9639cbf6af3
2022-03-28 21:59:34 -0400 to 2022-04-12 21:14:47 -0400
- Propagate nostarch edits to src
- Propagate updated test example code to nostarch snapshot
- Edits to nostarch edits
- edits from nostarch
- Fix error message for the example code
- update ch13-02 to reflect changes in rust-lang/book#2797
- Update to 1.59
- Edits to chapter 2 after tech review

## rust-by-example

4 commits in ec954f35eedf592cd173b21c05a7f80a65b61d8a..c2a98d9fc5d29c481d42052fbeccfde15ed03116
2022-03-22 11:09:06 -0300 to 2022-04-08 06:44:18 -0300
- Code highlight a variable (rust-lang/rust-by-example#1530)
- Add a comment to note that warnings may not be shown in a browser in the Variable Bindings section (rust-lang/rust-by-example#1529)
- Make all new types have UpperCamelCase names in code example in the Aliasing section (rust-lang/rust-by-example#1528)
- Replace `C` with C/C++ (rust-lang/rust-by-example#1527)

## rustc-dev-guide

6 commits in 155126b1d2e2cb01ddb1d7ba9489b90d7cd173ad..eeb5a83c15b6ae60df3e4f19207376b22c6fbc4c
2022-03-22 14:34:21 +0100 to 2022-04-11 23:29:48 +0900
- method-lookup.md improvements (rust-lang/rustc-dev-guide#1296)
- Consolidate crates.io convention section (rust-lang/rustc-dev-guide#1326)
- Update examples with 1.61.0-nightly (latest version) (rust-lang/rustc-dev-guide#1330)
- r-a: Use `python3 x.py` instead of `./x.py` (rust-lang/rustc-dev-guide#1335)
- Update miri.md: correct a minor typo (rust-lang/rustc-dev-guide#1334)
- Add example how lints can be feature gated