`OsStr` has historically kept its implementation details private out of
concern for locking us into a specific encoding on Windows.

This is an alternative to rust-lang#95290 which proposed specifying the encoding on Windows.  Instead, this
only specifies that for cross-platform code, `OsStr`'s encoding is a superset of UTF-8 and defines
rules for safely interacting with it

At minimum, this can greatly simplify the `os_str_bytes` crate and every
arg parser that interacts with `OsStr` directly (which is most of those
that support invalid UTF-8).

This option was introduced three years ago, but it's never been
meaningfully used, and `default` is the only acceptable value.

Also, I think the `Partition` trait presents an interface that is too
closely tied to the existing strategy and would probably be wrong for
other strategies. (My rule of thumb is to not make something generic
until there are at least two instances of it, to avoid this kind of
problem.)

Also, I don't think providing multiple partitioning strategies to the
user is a good idea, because the compiler already has enough obscure
knobs.

This commit removes the option, along with the `Partition` trait, and
the `Partitioner` and `DefaultPartitioning` types. I left the existing
code in `compiler/rustc_monomorphize/src/partitioning/default.rs`,
though I could be persuaded that moving it into
`compiler/rustc_monomorphize/src/partitioning/mod.rs` is better.

Within `compiler/rustc_monomorphize/src/partitioning/`, because the
previous commit removed the need for `default.rs` to be a separate file.

Because it's now the only file within
`compiler/rustc_monomorphize/src/partitioning/`.

Allow limited access to `OsStr` bytes

`OsStr` has historically kept its implementation details private out of
concern for locking us into a specific encoding on Windows.

This is an alternative to rust-lang#95290 which proposed specifying the encoding on Windows.  Instead, this
only specifies that for cross-platform code, `OsStr`'s encoding is a superset of UTF-8 and defines
rules for safely interacting with it

At minimum, this can greatly simplify the `os_str_bytes` crate and every
arg parser that interacts with `OsStr` directly (which is most of those
that support invalid UTF-8).

Tracking issue: rust-lang#111544

…llaumeGomez

Migrate  `item_proc_macro` to Askama

This PR migrates `item_proc_macro` to Askama

Refers rust-lang#108868

…trategy, r=wesleywiser

Remove `-Zcgu-partitioning-strategy`.

This option was introduced three years ago, but it's never been meaningfully used, and `default` is the only acceptable value.

Also, I think the `Partition` trait presents an interface that is too closely tied to the existing strategy and would probably be wrong for other strategies. (My rule of thumb is to not make something generic until there are at least two instances of it, to avoid this kind of problem.)

Also, I don't think providing multiple partitioning strategies to the user is a good idea, because the compiler already has enough obscure knobs.

This commit removes the option, along with the `Partition` trait, and the `Partitioner` and `DefaultPartitioning` types. I left the existing code in `compiler/rustc_monomorphize/src/partitioning/default.rs`, though I could be persuaded that moving it into
`compiler/rustc_monomorphize/src/partitioning/mod.rs` is better.

r? `@wesleywiser`

…r=WaffleLapkin

offset_of: don't require type to be `Sized`

Fixes rust-lang#112051

~~The RFC [explicitly forbids](https://rust-lang.github.io/rfcs/3308-offset_of.html#limitations) non-`Sized` types, but it looks like only the fields being recursed into were checked. The sized check also seemed to have been completely missing for tuples~~

…r=oli-obk

change `BorrowKind::Unique` to be a mutating `PlaceContext`

fixes rust-lang#112056

I believe that `BorrowKind::Unique` is a footgun in general, so I added a FIXME and opened rust-lang#112072. This is a bit too involved for this PR though.

…li-obk

Group rfcs tests

This moves all RFC tests to `tests/ui/rfcs/rfc-NNNN-title-title-title/...`

I had to rename some tests due to conflicts, but otherwise this is just a move.