Remove `in_band_lifetimes` from `rustc_privacy`

See #91867 for more information.

Remove `in_band_lifetimes` from `rustc_query_impl`

See #91867 for more information.

pass -Wl,-z,origin to set DF_ORIGIN when using rpath

DF_ORIGIN flag signifies that the object being loaded may make reference to the $ORIGIN substitution string.

Some implementations are just ignoring [DF_ORIGIN](http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#df_flags) and do [substitution](http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#substitution) for $ORIGIN if present (whatever DF_ORIGIN presence or not) like glibc. But some others mandate the present of DF_ORIGIN for the substitution (like OpenBSD).

Set the flag inconditionally if rpath is wanted.

One possible fallout is if the linker rejects `-z origin` option.

Rollup of 7 pull requests

Successful merges:

 - #87901 (Fix suggestion of additional `pub` when using `pub pub fn ...`)
 - #89090 (Lint bare traits in AstConv.)
 - #91818 (Show the unused type for `unused_results` lint)
 - #91910 (miri: lift restriction on extern types being the only field in a struct)
 - #91928 (Constify (most) `Option` methods)
 - #91975 (Move generator check earlier in inlining.)
 - #92016 (builtin_macros: allow external consumers for AsmArgs parsing)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

builtin_macros: allow external consumers for AsmArgs parsing

As discussed in Zulip (https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/parsing.20of.20AsmArgs.20for.20inline.20assembly), we need a function entry point that rustfmt can leverage from a pre-expansion context to get a more structured representation of the asm args without having to duplicate/maintain the token stream parsing

r? ```@Amanieu``` and/or ```@joshtriplett```

Move generator check earlier in inlining.

Inlining into generator may create references to other generators. For instance, inlining `Pin::<&mut from_generator::GenFuture<[generator1]>>::new_unchecked` into `generator2`. This cross reference can then create cycles when computing inlining for `generator1`.

In order to avoid this kind of surprises, we forbid all inlining into generators, and rely on LLVM to do the right thing. The existing `remove-zst-query-cycle` already ICEs in inline-mir mode, so we use it as test.

Split from #91743.

Constify (most) `Option` methods

r? ``@oli-obk``

miri: lift restriction on extern types being the only field in a struct

Fixes #91827.

r? ````@RalfJung````

Show the unused type for `unused_results` lint

I think it's helpful to know what type was unused when looking at these
warnings. The type will likely determine whether the result *should* be
used, or whether it should just be ignored.

Including the type also matches the behavior of the `must_use` lint:
unused `SomeType` that must be used.

Lint bare traits in AstConv.

Removing the lint from lowering allows to:
- make lowering querification easier;
- have the lint implementation in only one place.

r? `@estebank`

Fix suggestion of additional `pub` when using `pub pub fn ...`

Fix #87694.

Marked as draft to start with because I want to explore doing the same fix for `const const fn` and other repeated-but-valid keywords.

`@rustbot` label A-diagnostics D-invalid-suggestion T-compiler

Implement let-else type annotations natively

Tracking issue: #87335

Fixes #89688, fixes #89807, edit: fixes  #89960 as well

As explained in https://github.com/rust-lang/rust/issues/89688#issuecomment-940405082, the previous desugaring moved the let-else scrutinee into a dummy variable, which meant if you wanted to refer to it again in the else block, it had moved.

This introduces a new hir type, ~~`hir::LetExpr`~~ `hir::Let`, which takes over all the fields of `hir::ExprKind::Let(...)` and adds an optional type annotation. The `hir::Let` is then treated like a `hir::Local` when type checking a function body, specifically:

* `GatherLocalsVisitor` overrides a new `Visitor::visit_let_expr` and does pretty much exactly what it does for `visit_local`, assigning a local type to the `hir::Let` ~~(they could be deduplicated but they are right next to each other, so at least we know they're the same)~~
* It reuses the code in `check_decl_local` to typecheck the `hir::Let`, simply returning 'bool' for the expression type after doing that.

* ~~`FnCtxt::check_expr_let` passes this local type in to `demand_scrutinee_type`, and then imitates check_decl_local's pattern checking~~
* ~~`demand_scrutinee_type` (the blindest change for me, please give this extra scrutiny) uses this local type instead of of creating a new one~~
    * ~~Just realised the `check_expr_with_needs` was passing NoExpectation further down, need to pass the type there too. And apparently this Expectation API already exists.~~

Some other misc notes:

* ~~Is the clippy code supposed to be autoformatted? I tried not to give huge diffs but maybe some rustfmt changes simply haven't hit it yet.~~
* in `rustc_ast_lowering/src/block.rs`, I noticed some existing `self.alias_attrs()` calls in `LoweringContext::lower_stmts` seem to be copying attributes from the lowered locals/etc to the statements. Is that right? I'm new at this, I don't know.

Do array-slice equality via array equality, rather than always via slices

~~Draft because it needs a rebase after #91766 eventually gets through bors.~~

This enables the optimizations from #85828 to be used for array-to-slice comparisons too, not just array-to-array.

For example, <https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=5f9ba69b3d5825a782f897c830d3a6aa>
```rust
pub fn demo(x: &[u8], y: [u8; 4]) -> bool {
    *x == y
}
```
Currently writes the array to stack for no reason:
```nasm
	sub	rsp, 4
	mov	dword ptr [rsp], edx
	cmp	rsi, 4
	jne	.LBB0_1
	mov	eax, dword ptr [rdi]
	cmp	eax, dword ptr [rsp]
	sete	al
	add	rsp, 4
	ret

.LBB0_1:
	xor	eax, eax
	add	rsp, 4
	ret
```
Whereas with the change in this PR it just compares it directly:
```nasm
	cmp	rsi, 4
	jne	.LBB1_1
	cmp	dword ptr [rdi], edx
	sete	al
	ret

.LBB1_1:
	xor	eax, eax
	ret
```

Update Clippy

Only one day delayed! 😅

r? `@Manishearth`

Rustup

r? `@ghost`

changelog: none

DF_ORIGIN flag signifies that the object being loaded may make reference to the $ORIGIN substitution string.

Some implementations are just ignoring DF_ORIGIN and do substitution for $ORIGIN if present (whatever DF_ORIGIN pr

Set the flag inconditionally if rpath is wanted.

Update cargo

8 commits in a359ce16073401f28b84840da85b268aa3d37c88..fcef61230c3b6213b6b0d233a36ba4ebd1649ec3
2021-12-14 18:40:22 +0000 to 2021-12-17 02:30:38 +0000
- Minor docs change for `cargo test --help` (rust-lang/cargo#10210)
- Make clippy happy (rust-lang/cargo#10205)
- Enhance descriptions of issue templates (rust-lang/cargo#10202)
- Add workaround for sporadic kills when building on Macos (rust-lang/cargo#10196)
- Detect filesystem loop during walking the projects (rust-lang/cargo#10188)
- Error about not having any crates with documentation (rust-lang/cargo#10204)
- Don't document libs with doc=false (rust-lang/cargo#10201)
- Bumps up tar to 0.4.36 (rust-lang/cargo#10198)

rustdoc: Pretty-print assoc const defaults on-demand

This should improve performance, clean up the code, and help pave the
way for #83035.

Implement normalize_erasing_regions queries in terms of 'try' version

Attempt to lessen performance regression caused by https://github.com/rust-lang/rust/pull/91255

r? `@jackh726`

Rollup of 7 pull requests

Successful merges:

 - #91172 (Warn when a `#[test]`-like built-in attribute macro is present multiple times.)
 - #91796 (Fix since attribute for const_manually_drop feature)
 - #91879 (Remove `in_band_lifetimes` from `rustc_borrowck`)
 - #91947 (Add `io::Error::other`)
 - #91967 (Pull in libdevstat on FreeBSD)
 - #91987 (Add module documentation for rustdoc passes)
 - #92001 (Fix default_method_body_is_const when used across crates)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Fix #91306 by deriving all access from a single *mut T

Fixes #91306.

The previous code is invalid because the first argument to `copy_nonoverlapping` is invalidated by the mutable borrow taken out to construct the second argument.

I believe this patch fixes that, and this code should now pass Miri with `-Ztag-raw-pointers`, ~~but I'm currently stuck trying to run my reproducer with a this patched version of the standard library (alternatively, running Miri on the standard library tests itself would suffice).~~ Ralf walked me through this on Zulip.

I've also added fixes for 7 more problems other than those I reported. Most of them are easy to hit by calling sort_unstable on random arrays. I don't have reproducers for every change, but they seem pretty clear-cut to me. But I did only start learning stacked borrows 2 days ago so that might be a large dash of Dunning-Kruger.

Fix default_method_body_is_const when used across crates

r? `@oli-obk`

unblocks #91439.

Add module documentation for rustdoc passes

These are currently documented at https://rustc-dev-guide.rust-lang.org/rustdoc-internals.html#hot-potato but can easily go out of date. We'd like to document them in place and link to https://doc.rust-lang.org/nightly/nightly-rustc/rustdoc/passes/index.html

[Discussed on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/266220-rustdoc/topic/moving.20pass.20docs/near/265058351).

r? `@camelid`

Pull in libdevstat on FreeBSD

Similar to https://github.com/rust-lang/rust/pull/90495, spotted in https://github.com/rust-lang/rust/pull/91909.

Add `io::Error::other`

This PR adds a small utility constructor, `io::Error::other`, a shorthand for `io::Error::new(io::ErrorKind::Other, err)`, something I find myself writing often.

For some concrete stats, a quick search on [grep.app](https://grep.app) shows that more than half of the uses of `io::Error::new` use `ErrorKind::Other`:
```
Error::new\((?:std::)?(?:io::)?ErrorKind:: => 3,898 results
Error::new\((?:std::)?(?:io::)?ErrorKind::Other => 2,186 results
```

Remove `in_band_lifetimes` from `rustc_borrowck`

See #91867 for more information.

Fix since attribute for const_manually_drop feature

const_manually_drop was stabilized in 1.32 as mentioned in
https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1320-2019-01-17

Warn when a `#[test]`-like built-in attribute macro is present multiple times.

Fixes #90979.

Most of these problems originate in use of get_unchecked_mut.

When calling ptr::copy_nonoverlapping, using get_unchecked_mut for both
arguments causes the borrow created to make the second pointer to invalid the
first.

The pairs of identical MaybeUninit::slice_as_mut_ptr calls similarly
invalidate each other.

There was also a similar borrow invalidation problem with the use of
slice::get_unchecked_mut to derive the pointer for the CopyOnDrop.

rustdoc: don't clone already owned `Path` and modify it inplace