Revert "Auto merge of #80357 - c410-f3r:new-hir-let, r=matthewjasper"

[richkadel]

This reverts commit 2a6fb9a, reversing
changes made to 2bd17c1.

Reverts: #80357
Fixes: #88307

From the PR author's initial comment, it sounds like they may not have time to fix this quickly. Since this is a high priority regression issue, I prepared this revert.

[rust-highfive]

Some changes occurred in src/tools/rustfmt.

cc @calebcartwright

Some changes occurred in src/tools/clippy.

cc @rust-lang/clippy

[rust-highfive]

r? @michaelwoerister

(rust-highfive has picked a reviewer for you, use r? to override)

[richkadel]

r? @tmandry

[rust-log-analyzer]

The job mingw-check failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

    Checking url v2.2.2
    Checking semver v0.11.0
    Checking clippy_utils v0.1.56 (/checkout/src/tools/clippy/clippy_utils)
    Checking toml v0.5.7
error[E0422]: cannot find struct, variant or union type `Block` in this scope
   --> src/tools/clippy/clippy_utils/src/higher.rs:316:36
    |
316 |             if let ExprKind::Block(Block { stmts: [], expr: Some(expr), .. }, _) = arm.body.kind;
    |
help: consider importing one of these items
    |
6   | use crate::Block;
---

error[E0609]: no field `kind` on type `&_`
   --> src/tools/clippy/clippy_utils/src/higher.rs:317:56
    |
317 |             if let ExprKind::Call(_, call_args) = expr.kind;

Some errors have detailed explanations: E0422, E0609.
For more information about an error, try `rustc --explain E0422`.
error: could not compile `clippy_utils` due to 2 previous errors

[c410-f3r]

???

Isn't it possible to wait a few more days? The fix will be delivered as soon as possible

[richkadel]

Yes! It wasn't clear that you had time, but if you're working on a fix, that would be better than reverting. Thanks!

[richkadel]

Just a note, for the record, I think this revert is risky.

Basic rustc tests passed locally. The clippy failure above is because I didn't notice clippy changed, and didn't try to compile or test it on the first pass. There were more merge conflicts in clippy. I did my best to resolve those (locally). One test is still failing for me, but I'm not going to continue working on this as long as @c410-f3r is working on the fix.

The original changes were broad in scope, and there have been other changes on top of the original PR, some of which build on the new IfLet types and features. A revert will end up reverting parts of other PRs, and somehow we would need to catch and track them, and readdressed later.

Even more concerning, it's not clear that the revert merges (git-automated and my manual conflict resolution) are going to result in the intended behavior. In some cases, large blocks were changed, and I tried to choose the better block to keep, and then fix compiler errors. Other than validating via tests (which isn't always definitive), I (or git) could have easily missed something subtle but important.

[bors]

☔ The latest upstream changes (presumably #88328) made this pull request unmergeable. Please resolve the merge conflicts.

[flip1995]

There were more merge conflicts in clippy.

Yes. @camsteffen already worked on fixing the Clippy fallout in some PRs. So if we revert this, all those PRs would have to be reverted first.

I really want to avoid this revert, if at all possible.

[jackh726]

Don't think we still need this...proper fix has been merged.