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.

The docs for `Iterator::unzip` explain that it is kind of an inverse operation to `Iterator::zip` and guide the reader to the `zip` docs, but the `zip` docs don't let the user know that they can undo the `zip` operation with `unzip`. This change modifies the docs to help the user find `unzip`.

Co-authored-by: Mara Bos <m-ou.se@m-ou.se>

…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``

…comment, r=petrochenkov

Improve diagnostics for unterminated nested block comment

close rust-lang#95283

(This is my first time try to messing around with rust compiler and might get a lot of things wrong... 🙇 )

…inline, r=oli-obk

Inline `shallow_resolve_ty` into `ShallowResolver`

addresses fixme I found in infcx

…ylan-DPC

couple of clippy::complexity fixes

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

docs: add link from zip to unzip

The docs for `Iterator::unzip` explain that it is kind of an inverse operation to `Iterator::zip` and guide the reader to the `zip` docs, but the `zip` docs don't let the user know that they can undo the `zip` operation with `unzip`. This change modifies the docs to help the user find `unzip`.