…3, r=petrochenkov"

This reverts commit 91b18a0, reversing
changes made to 9aedec9.

…nce, r=pnkfelix"

This reverts commit a70dc29, reversing
changes made to ceae371.

It has a single use. This makes the `let` handling case in
`parse_stmt_without_recovery` more similar to the statement path and
statement expression cases.

`parse_expr_assoc_with` has an awkward structure -- sometimes the lhs is
already parsed. This commit splits the post-lhs part into a new method
`parse_expr_assoc_rest_with`, which makes everything shorter and
simpler.

…nce-2, r=pnkfelix"

This reverts commit 31fe962, reversing
changes made to f203078.

…nce, r=pnkfelix"

This reverts commit 2724aea, reversing
changes made to d929a42.

…9, r=petrochenkov"

This reverts commit 977c5fd, reversing
changes made to 24c94f0.

…nce, r=pnkfelix"

This reverts commit 13314df, reversing
changes made to 6e534c7.

…hanges

It can be done more concisely.

When collecting tokens there are two kinds of range:
- a range relative to the parser's full token stream (which we get when
  we are parsing);
- a range relative to a single AST node's token stream (which we use
  within `LazyAttrTokenStreamImpl` when replacing tokens).

These are currently both represented with `Range<u32>` and it's easy to
mix them up -- until now I hadn't properly understood the difference.

This commit introduces `ParserRange` and `NodeRange` to distinguish
them. This also requires splitting `ReplaceRange` in two, giving the new
types `ParserReplacement` and `NodeReplacement`. (These latter two names
reduce the overloading of the word "range".)

The commit also rewrites some comments to be clearer.

The end result is a little more verbose, but much clearer.

… these lists

This file tests for UB in `reduce_add`, but those are reimplemented by explicitly using the associativity specified by Intel

rustdoc: Remove OpaqueTy

r? `@ghost`

Apparently this works lol?!?

try-job: aarch64-apple

…hanges, r=pnkfelix

Revert recent changes to dead code analysis

This is a revert to recent changes to dead code analysis, namely:
* efdf219 Rollup merge of rust-lang#128104 - mu001999-contrib:fix/128053, r=petrochenkov
* a70dc29 Rollup merge of rust-lang#127017 - mu001999-contrib:dead/enhance, r=pnkfelix
* 31fe962 Rollup merge of rust-lang#127107 - mu001999-contrib:dead/enhance-2, r=pnkfelix
* 2724aea Rollup merge of rust-lang#126618 - mu001999-contrib:dead/enhance, r=pnkfelix
* 977c5fd Rollup merge of rust-lang#126315 - mu001999-contrib:fix/126289, r=petrochenkov
* 13314df Rollup merge of rust-lang#125572 - mu001999-contrib:dead/enhance, r=pnkfelix

There is an additional change stacked on top, which suppresses false-negatives that were masked by this work. I believe the functions that are touched in that code are legitimately unused functions and the types are not reachable since this `AnonPipe` type is not publically reachable -- please correct me if I'm wrong cc `@NobodyXu` who added these in #rust-lang#127153.

Some of these reverts (rust-lang#126315 and rust-lang#126618) are only included because it makes the revert apply cleanly, and I think these changes were only done to fix follow-ups from the other PRs?

I apologize for the size of the PR and the churn that it has on the codebase (and for reverting `@mu001999's` work here), but I'm putting this PR up because I am concerned that we're making ad-hoc changes to fix bugs that are fallout of these PRs, and I'd like to see these changes reimplemented in a way that's more separable from the existing dead code pass. I am happy to review any code to reapply these changes in a more separable way.

cc `@mu001999`
r? `@pnkfelix`

Fixes rust-lang#128272
Fixes rust-lang#126169

Update the stdarch submodule

cc `@tgross35` `@Amanieu`
r? `@tgross35`

try-job: x86_64-rust-for-linux

…s, r=petrochenkov

Still more `cfg` cleanups

Found while looking closely at `cfg`/`cfg_attr` processing code.

r? `@petrochenkov`

…r-errors

MIR required_consts, mentioned_items: ensure we do not forget to fill these lists

Bodies initially get created with empty required_consts and mentioned_items, but at some point those should be filled. Make sure we notice when that is forgotten.