Each pattern in a match arm has its own copy of the match guard in MIR,
with its own temporary, so it has to be dropped before the the guards
are joined to the single copy of the arm.

Include debug info for the allocator shim

Issue Details:
In some cases it is necessary to generate an "allocator shim" to forward various Rust allocation functions (e.g., `__rust_alloc`) to an underlying function (e.g., `malloc`). However, since this allocator shim is a manually created LLVM module it is not processed via the normal module processing code and so no debug info is generated for it (if debugging info is enabled).

Fix Details:
* Modify the `debuginfo` code to allow creating debug info for a module without a `CodegenCx` (since it is difficult, and expensive, to create one just to emit some debug info).
* After creating the allocator shim add in basic debug info.

fix(rustc_lint): better detect when parens are necessary

Fixes #88519

CrateLocator refactorings

This makes the `CrateLocator` a lot cleaner IMHO and much more self-contained. The last commit removes `extra_filename` from the crate metadata. This is an **insta-stable** change as it allows a crate like `libfoo-abc.rlib` to be used as dependency and then be renamed as `libfoo-bcd.rlib` while still being found as indirect dependency. This may reduce performance when there are a lot of versions of the same crate available as the extra filename won't be used to do an early rejection of crates before trying to load metadata, but it makes the logic to find the right filename a lot cleaner.

Bump version to 1.57

r? `@Mark-Simulacrum`

Detect bare blocks with type ascription that were meant to be a `struct` literal

Address part of #34255.

Potential improvement: silence the other knock down errors in `issue-34255-1.rs`.

Add regression test for a spurious import

This PR adds a test that verifies that the bug described in the linked issue does not creep back into the code. In essence it checks that compiling some specific code (that uses 128 bit multiplication) with a specific set of compiler options does not lead to a spurious import of a panic function.

I noticed that other wasm tests use `# only-wasm32-bare` in their `Makefile`. This will skip the test for me. I did not find out how to run this test locally. Maybe someone can help.

closes #78744
r? `@jyn514`

Fix drop handling for `if let` expressions

MIR lowering for `if let` expressions is now more complicated now that
`if let` exists in HIR. This PR adds a scope for the variables bound in
an `if let` expression and then uses an approach similar to how we
handle loops to ensure that we reliably drop the correct variables.

Closes #88307
cc `@flip1995` `@richkadel` `@c410-f3r`

sunos systems add sanitizer supported.

Move global analyses from lowering to resolution

Split off https://github.com/rust-lang/rust/pull/87234

r? `@petrochenkov`

Address part of #34255.

Potential improvement: silence the other knock down errors in
`issue-34255-1.rs`.

Rollup of 7 pull requests

Successful merges:

 - #88202 (Add an example for deriving PartialOrd on enums)
 - #88483 (Fix LLVM libunwind build for non-musl targets)
 - #88507 (Add test case for using `slice::fill` with MaybeUninit)
 - #88557 (small const generics cleanup)
 - #88579 (remove redundant / misplaced sentence from docs)
 - #88610 (Update outdated docs of array::IntoIter::new.)
 - #88613 (Update primitive docs for rust 2021.)

Failed merges:

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

Update primitive docs for rust 2021.

Fixes https://github.com/rust-lang/rust/issues/87701

Update outdated docs of array::IntoIter::new.

remove redundant / misplaced sentence from docs

Removes sentence that seems to have drifted down into the examples section. Luckily, someone already added an explanation of what happens with packed structs back into the initial section of the doc entry and this wayward sentence can likely just be deleted.

small const generics cleanup

Add test case for using `slice::fill` with MaybeUninit

Adds test for #87891

Looks alright? `@RalfJung`
Fixes #87891

Fix LLVM libunwind build for non-musl targets

Broken in #85600. AFAICT, [only musl, mingw, and wasm](https://github.com/rust-lang/rust/blob/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_target/src/spec/crt_objects.rs#L128-L132) should use the “self-contained” logic in rustbuild.

Add an example for deriving PartialOrd on enums

For some reason, I always forget which variants are smaller and which
are larger when you derive PartialOrd on an enum. And the wording in the
current docs is not entirely clear to me.

So, I often end up making a small enum, deriving PartialOrd on it, and
then writing a `#[test]` with an assert that the top one is smaller than
the bottom one (or the other way around) to figure out which way the
deriving goes.

So then I figured, it would be great if the standard library docs just
had that example, so if I keep forgetting, at least I can figure it out
quickly by looking at std's docs.

Refactor unsized suggestions

`@rustbot` label +A-diagnostics +A-traits +A-typesystem +C-cleanup +T-compiler

expand: Treat more macro calls as statement macro calls

This PR implements the suggestion from https://github.com/rust-lang/rust/pull/87981#issuecomment-906641052 and treats fn-like macro calls inside `StmtKind::Item` and `StmtKind::Semi` as statement macro calls, which is consistent with treatment of attribute invocations in the same positions and with token-based macro expansion model in general.

This also allows to remove a special case in `NodeId` assignment (previously tried in #87779), and to use statement `NodeId`s for linting (`assign_id!`).

r? `@Aaron1011`

Point at unclosed delimiters as part of the primary MultiSpan

Both the place where the parser encounters a needed closed delimiter and
the unclosed opening delimiter are important, so they should get the
same level of highlighting in the output.

_Context: https://twitter.com/mwk4/status/1430631546432675840_

Path remapping: Make behavior of diagnostics output dependent on presence of --remap-path-prefix.

This PR fixes a regression (#87745) with `--remap-path-prefix` where the flag stopped causing diagnostic messages to be remapped as well. The regression was introduced in https://github.com/rust-lang/rust/pull/83813 where we erroneously assumed that remapping of diagnostic messages was not desired anymore (because #70642 partially undid that functionality with nobody objecting).

The issue is fixed by making `--remap-path-prefix` remap diagnostic messages again, including for paths that have been remapped in upstream crates (e.g. the standard library). This means that "sysroot-localization" (implemented in #70642) is also disabled if `rustc` is invoked with `--remap-path-prefix`. The assumption is that once someone starts explicitly remapping paths they also don't want paths to their local Rust installation in their build output.

In the future we might want to give more fine-grained control over this behavior via compiler flags (see https://github.com/rust-lang/rfcs/pull/3127 for a related RFC). For now this PR is intended as a regression fix.

This PR is an alternative to https://github.com/rust-lang/rust/pull/88191, which makes diagnostic messages be remapped unconditionally. That approach, however, would effectively revert #70642.

Fixes https://github.com/rust-lang/rust/issues/87745.

cc `@cbeuw`
r? `@ghost`

Preserve most sub-obligations in the projection cache

Fixes https://github.com/rust-lang/rust/issues/85360

When we evaluate a projection predicate, we may produce sub-obligations. During trait evaluation, evaluating these sub-obligations might cause us to produce `EvaluatedToOkModuloRegions`.

When we cache the result of projection in our projection cache, we try to throw away some of the sub-obligations, so that we don't need to re-evaluate/process them the next time we need to perform this particular projection. However, we may end up throwing away predicates that will (recursively) evaluate to `EvaluatedToOkModuloRegions`. If we do, then the result of evaluating a predicate will depend on the state of the predicate cache - this is global untracked state, which interacts badly with incremental compilation.

To fix this, we now only discard global predicates that evaluate to `EvaluatedToOk`. This ensures that any predicates that (may) evaluate to `EvaluatedToOkModuloRegions` are kept in the cache, and influence the results of any queries which perform this projection.

Rollup of 12 pull requests

Successful merges:

 - #88177 (Stabilize std::os::unix::fs::chroot)
 - #88505 (Use `unwrap_unchecked` where possible)
 - #88512 (Upgrade array_into_iter lint to include Deref-to-array types.)
 - #88532 (Remove single use variables)
 - #88543 (Improve closure dummy capture suggestion in macros.)
 - #88560 (`fmt::Formatter::pad`: don't call chars().count() more than one time)
 - #88565 (Add regression test for issue 83190)
 - #88567 (Remove redundant `Span` in `QueryJobInfo`)
 - #88573 (rustdoc: Don't panic on ambiguous inherent associated types)
 - #88582 (Implement #88581)
 - #88589 (Correct doc comments inside `use_expr_visitor.rs`)
 - #88592 (Fix ICE in const check)

Failed merges:

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

Fix ICE in const check

Fixes https://github.com/rust-lang/rust/issues/88433

Correct doc comments inside `use_expr_visitor.rs`

Just a simple update. I haven't changed any content inside the comments, as they still seem correct. Have a wonderful rest of the day 🙃

Implement #88581

See #88581 for details. This API was discussed on Zulip.

`@rustbot` label: +T-libs-api +S-waiting-on-review

r? `@joshtriplett`

rustdoc: Don't panic on ambiguous inherent associated types

Instead, return `Type::Infer` since compilation should fail anyway.
That's how rustdoc handles `hir::TyKind::Err`s, so this just extends
that behavior to `ty::Err`s when analyzing associated types.

For some reason, the error is printed twice with rustdoc (though only
once with rustc). I'm not sure why that is, but it's better than
panicking.

This commit also makes rustdoc fail early in the non-projection,
non-error case, instead of returning a `Res::Err` that would likely
cause rustdoc to panic later on. This change is originally from #88379.

r? `@GuillaumeGomez`

Remove redundant `Span` in `QueryJobInfo`

Previously, `QueryJobInfo` was composed of two parts: a `QueryInfo` and
a `QueryJob`. However, both `QueryInfo` and `QueryJob` have a `span`
field, which seem to be the same. So, the `span` was recorded twice.

Now, `QueryJobInfo` is composed of a `QueryStackFrame` (the other field
of `QueryInfo`) and a `QueryJob`. So, now, the `span` is only recorded
once.

Add regression test for issue 83190

Reduced from `bioyino-metric` by ````@hellow554```` and myself.

Closes #83190.

r? ````@spastorino````

`fmt::Formatter::pad`: don't call chars().count() more than one time

First commit merges two branches of match to call chars().count() only once: that should be faster if this method hits place of 3rd (previous) branch, plus quarter shorter.
Second commit fixes some clippy lints while i'm here (should it be separate PR?).

Improve closure dummy capture suggestion in macros.

Fixes some cases of https://github.com/rust-lang/rust/issues/88440

Fixes https://crater-reports.s3.amazonaws.com/pr-87190-3/try%23a7a572ce3edd6d476191fbfe92c9c1986e009b34/reg/rcodec-1.0.1/log.txt

Remove single use variables

Upgrade array_into_iter lint to include Deref-to-array types.

Fixes https://github.com/rust-lang/rust/issues/88099

Fixes the issue mentioned here: https://github.com/rust-lang/rust/pull/84147#issuecomment-819000436