…r=fee1-dead

Unify `tcx.constness` query and param env constness checks

The checks that we do in the `constness` query seem inconsistent with the checks that we do to determine if an item's param-env is const, so I merged them into the `constness` query and call that from the `param_env` query.

I'm not sure if this totally makes sense -- is there a case where `tcx.param_env()` would return a const param-env for an item whose `tcx.constness()` is `Constness::NotConst`? Because if not, it seems a bit dangerous that these two differ.

Luckily, not many places actually use `tcx.constness()`, and the checks in `tcx.param_env()` seem stricter than the checks in `tcx.constness()` (at least for the types of items we type-check).

Also, due to the way that `tcx.param_env()` is implemented, it _never_ used to return a const param-env for a item coming from a different crate, which also seems dangerous (though also probably not weaponizable currently, because we seldom actually compute the param-env for a non-local item).

…r=fee1-dead

Unify `tcx.constness` query and param env constness checks

The checks that we do in the `constness` query seem inconsistent with the checks that we do to determine if an item's param-env is const, so I merged them into the `constness` query and call that from the `param_env` query.

I'm not sure if this totally makes sense -- is there a case where `tcx.param_env()` would return a const param-env for an item whose `tcx.constness()` is `Constness::NotConst`? Because if not, it seems a bit dangerous that these two differ.

Luckily, not many places actually use `tcx.constness()`, and the checks in `tcx.param_env()` seem stricter than the checks in `tcx.constness()` (at least for the types of items we type-check).

Also, due to the way that `tcx.param_env()` is implemented, it _never_ used to return a const param-env for a item coming from a different crate, which also seems dangerous (though also probably not weaponizable currently, because we seldom actually compute the param-env for a non-local item).

…r=fee1-dead

Unify `tcx.constness` query and param env constness checks

The checks that we do in the `constness` query seem inconsistent with the checks that we do to determine if an item's param-env is const, so I merged them into the `constness` query and call that from the `param_env` query.

I'm not sure if this totally makes sense -- is there a case where `tcx.param_env()` would return a const param-env for an item whose `tcx.constness()` is `Constness::NotConst`? Because if not, it seems a bit dangerous that these two differ.

Luckily, not many places actually use `tcx.constness()`, and the checks in `tcx.param_env()` seem stricter than the checks in `tcx.constness()` (at least for the types of items we type-check).

Also, due to the way that `tcx.param_env()` is implemented, it _never_ used to return a const param-env for a item coming from a different crate, which also seems dangerous (though also probably not weaponizable currently, because we seldom actually compute the param-env for a non-local item).

…r=fee1-dead

Unify `tcx.constness` query and param env constness checks

The checks that we do in the `constness` query seem inconsistent with the checks that we do to determine if an item's param-env is const, so I merged them into the `constness` query and call that from the `param_env` query.

I'm not sure if this totally makes sense -- is there a case where `tcx.param_env()` would return a const param-env for an item whose `tcx.constness()` is `Constness::NotConst`? Because if not, it seems a bit dangerous that these two differ.

Luckily, not many places actually use `tcx.constness()`, and the checks in `tcx.param_env()` seem stricter than the checks in `tcx.constness()` (at least for the types of items we type-check).

Also, due to the way that `tcx.param_env()` is implemented, it _never_ used to return a const param-env for a item coming from a different crate, which also seems dangerous (though also probably not weaponizable currently, because we seldom actually compute the param-env for a non-local item).

Rollup of 7 pull requests

Successful merges:

 - rust-lang#102623 (translation: eager translation)
 - rust-lang#102719 (Enforce alphabetical sorting with tidy)
 - rust-lang#102830 (Unify `tcx.constness` query and param env constness checks)
 - rust-lang#102883 (Fix stabilization of `feature(half_open_range_patterns)`)
 - rust-lang#102927 (Fix `let` keyword removal suggestion in structs)
 - rust-lang#102936 (rustdoc: remove unused CSS `nav.sum`)
 - rust-lang#102940 (Update books)

Failed merges:

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

Rollup of 7 pull requests

Successful merges:

 - rust-lang#102623 (translation: eager translation)
 - rust-lang#102769 (Clean up rustdoc startup)
 - rust-lang#102830 (Unify `tcx.constness` query and param env constness checks)
 - rust-lang#102847 (impl AsFd and AsRawFd for io::{Stdin, Stdout, Stderr}, not the sys versions)
 - rust-lang#102883 (Fix stabilization of `feature(half_open_range_patterns)`)
 - rust-lang#102936 (rustdoc: remove unused CSS `nav.sum`)
 - rust-lang#102940 (Update books)

Failed merges:

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

Revert "Unify tcx.constness and param env constness checks"

Too much of a perf regression rust-lang#102975 (comment), and an attempt in rust-lang#103263 didn't fix it except for just a tiny bit.

This change isn't really needed (see rust-lang#102830 (comment)), so this should be an easy revert.

Revert "Unify tcx.constness and param env constness checks"

Too much of a perf regression rust-lang/rust#102975 (comment), and an attempt in #103263 didn't fix it except for just a tiny bit.

This change isn't really needed (see rust-lang/rust#102830 (comment)), so this should be an easy revert.

Rollup of 7 pull requests

Successful merges:

 - rust-lang#102623 (translation: eager translation)
 - rust-lang#102719 (Enforce alphabetical sorting with tidy)
 - rust-lang#102830 (Unify `tcx.constness` query and param env constness checks)
 - rust-lang#102883 (Fix stabilization of `feature(half_open_range_patterns)`)
 - rust-lang#102927 (Fix `let` keyword removal suggestion in structs)
 - rust-lang#102936 (rustdoc: remove unused CSS `nav.sum`)
 - rust-lang#102940 (Update books)

Failed merges:

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