This commit moves `transparent_newtype_field` and `is_zst` to
`LateContext` where they are used, rather than being on the `VariantDef`
and `TyS` types.

Signed-off-by: David Wood <david@davidtw.co>

Stabilize the following methods of `Option` as const:
 - `is_some`
 - `is_none`
 - `as_ref`

Possible because of stabilization of rust-lang#49146 (Allow if and match in constants).

Part of rust-lang#76268

This is very similar to the existing `Box<[T; N]>: TryFrom<Box<[T]>>`, but allows avoiding the `shrink_to_fit` if you have a vector and not a boxed slice.

Thanks, Amanieu

Co-authored-by: Amanieu d'Antras <amanieu@gmail.com>

…here possible

Co-authored-by: Ivan Tham <pickfire@riseup.net>

…onversion)

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

…ts (clippy::unnecessary_lazy_evaluations)

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

…acrum

deny(unsafe_op_in_unsafe_fn) in libstd/path.rs

The libstd/path.rs part of rust-lang#73904 . Wraps the two calls to an unsafe fn Initializer::nop() in an unsafe block.

…ion, r=eddyb

lint/ty: move fns to avoid abstraction violation

This PR moves `transparent_newtype_field` and `is_zst` to `LateContext` where they are used, rather than being on the `VariantDef` and `TyS` types, hopefully addressing @eddyb's concern [from this comment](rust-lang#74340 (comment)).

Add test for checking duplicated branch or-patterns

This adds a regression test for checking `or-patterns` in MIR as shown in rust-lang#75439.
This doesn't introduce a fix as I'm not sure where it would go(I suspect maybe here: src/librustc_mir_build/build/matches/mod.rs), and I'm not particularly able to fix it.

cc: @lzutao

Stabilize some Option methods as const

Stabilize the following methods of `Option` as const:
 - `is_some`
 - `is_none`
 - `as_ref`

These methods are currently const under the unstable feature `const_option` (tracking issue: rust-lang#67441).
I believe these methods to be eligible for stabilization because of the stabilization of rust-lang#49146 (Allow if and match in constants) and the trivial implementations, see also:  [PR#75463](rust-lang#75463).

Related: rust-lang#76225

Add `[T; N]: TryFrom<Vec<T>>` (insta-stable)

This is very similar to the [existing](https://doc.rust-lang.org/nightly/std/convert/trait.TryFrom.html#impl-TryFrom%3CBox%3C%5BT%5D%3E%3E) `Box<[T; N]>: TryFrom<Box<[T]>>`, but allows avoiding the `shrink_to_fit` if you have a vector and not a boxed slice.

Like the slice equivalents of this, it fails if the length of the vector is not exactly `N`.
This uses `Vec<T>` as the `Error` type to return the input, like how the `Rc<[T]> -> Rc<[T; N]>` (and Arc) ones also reflect the input directly in the error type.

```rust
#[stable(feature = "array_try_from_vec", since = "1.47.0")]
impl<T, const N: usize> TryFrom<Vec<T>> for [T; N] {
    type Error = Vec<T>;
    fn try_from(mut vec: Vec<T>) -> Result<[T; N], Vec<T>>;
}
```

Inspired by this zulip thread: https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/APIs.20for.20getting.20stuff.20from.20a.20Vec.20by.20owned/near/209048103

Clean up vec benches bench_in_place style

do not inline black_box when building for Miri

We cannot do the assembly trick in Miri, but let's at least make sure MIR inlining does not circumvent the black_box.

Also use black_box instead of local optimization barriers in a few const tests.

…r=dtolnay

Add associated constant `BITS` to all integer types

Recently I've regularly come across this snippet (in a few different crates, including `core` and `std`):
```rust
std::mem::size_of<usize>() * 8
```

I think it's time for a `usize::BITS`.

assert ScalarMaybeUninit size

I noticed most low-level Miri types have such an assert but `ScalarMaybeUninit` does not, so let's add that. Good t see that the `Option`-like optimization kicks in and this is no bigger than `Scalar`. :)

r? @oli-obk

give *even better* suggestion when matching a const range

notice that the err already has "constant defined here"
so this is now *exceedingly clear*

extension to rust-lang#76222

r? @estebank

don't convert types to the same type with try_into (clippy::useless_conversion)

Give a better error message when x.py uses the wrong stage for CI

r? @shepmaster

…yn514

Build fixes for RISC-V 32-bit Linux support

This fixes build issues with the 32-bit RISC-V port.