This reverts commit 3ece63b.

Remove Select trait

I realized that our `select` implementation predated `Simd` being generic over element type, and we don't really need the `Select` trait at all. The function signature is much simpler now (generic over element type, rather than over the entire vector). This did require changing mask select to be a different function, but I think that's fine considering they're not necessarily vectors.

See rust-lang#91867

This was mostly straightforward. In several places, I take advantage
of the fact that lifetimes are non-hygenic: a macro declares the
'tcx' lifetime, which is then used in types passed in as macro
arguments.

`render/context` always runs after `run_global_context`, so it was always set to `true`.

This is a holdover from when rustdoc allowed configuring passes, but the `collapse-docs` pass was
removed ages ago, and the ability to configure passes is about to be removed.

Revert "Temporarily rename int_roundings functions to avoid conflicts"

This reverts commit 3ece63b.

This should be okay because rust-lang#90329 has been merged.

r? `@joshtriplett`

…oli-obk

Remove `in_band_lifetimes` from `rustc_middle`

See rust-lang#91867

This was mostly straightforward. In several places, I take advantage
of the fact that lifetimes are non-hygenic: a macro declares the
'tcx' lifetime, which is then used in types passed in as macro
arguments.

Sync portable-simd to fix libcore build for AVX-512 enabled targets

Fixes rust-lang#91484 (comment)
cc ``@workingjubilee``

Enable `#[thread_local]` for all windows-msvc targets

As it stands, `#[thread_local]` is enabled haphazardly for msvc. It seems all 64-bit targets have it enabled, but not 32-bit targets unless they're also UWP targets (perhaps because UWP was added more recently?). So this PR simply enables it for 32-bit targets as well. I can't think of a reason not to and I've confirmed by running tests locally which pass.

See also rust-lang#91659

Update example code for Vec::splice to change the length

The current example for `Vec::splice` illustrates the replacement of a section of length 2 with a new section of length 2. This isn't a particularly interesting case for splice, and makes it look a bit like a shorthand for the kind of manipulations that could be done with a mutable slice.

In order to provide a stronger example, this updates the example to use different lengths for the source and destination regions, and uses a slice from the middle of the vector to illustrate that this does not necessarily have to be at the beginning or the end.

Resolves rust-lang#92067

…eGomez

rustdoc: Remove unused `collapsed` field

`render/context` always runs after `run_global_context`, so it was always set to `true`.

This is a holdover from when rustdoc allowed configuring passes, but the `collapse-docs` pass was
removed ages ago, and the ability to configure passes is about to be removed.

Found while reviewing rust-lang#91305.

rustdoc: Remove unnecessary `need_backline` function

r? `@GuillaumeGomez`