When bootstrap compiles native dependencies like LLVM, it should set
CMAKE_SYSTEM_NAME for the target system; otherwise cmake may not
identify that it is cross-compiling.

In particular, when building a Linux rustc on a macOS host, cmake was
including `-isysroot /path/to/macOS.sdk` options that caused things to
break.  By setting `CMAKE_SYSTEM_NAME=Linux` when building for Linux
targets, the macOS SDK is no longer passed as sysroot to the compiler.

- Separate out functions so that each unit test doesn't create a file on disk
- Add a few unit tests

Notably, verifying that we generate valid toml relies on python 3.11 so
we can use `tomllib`.

This also fixes a regression from
rust-lang#106085 which stopped testing that
we support python2 in PR CI.

This makes a bit more sense — iter impl converts to slice first, while
slice impl used to create iter, doing unnecessary conversions.

…lacrum

Set `CMAKE_SYSTEM_NAME` for Linux targets

When bootstrap compiles native dependencies like LLVM, it should set `CMAKE_SYSTEM_NAME` for the target system; otherwise cmake may not identify that it is cross-compiling.

In particular, when building a Linux rustc on a macOS host, cmake was including `-isysroot /path/to/macOS.sdk` options that caused things to break.  By setting `CMAKE_SYSTEM_NAME=Linux` when building for Linux targets, the macOS SDK is no longer passed as sysroot to the compiler.

r? bootstrap

rustdoc: Correctly merge import's and its target's docs in one more case

Fixes rust-lang#108334.
Fixes rust-lang#108378.
Fixes rust-lang#108658.

…lacrum

Add tests for configure.py

I highly recommend reviewing this with whitespace disabled.

Notably, verifying that we generate valid toml relies on python 3.11 so
we can use `tomllib`, so this also switches`x86_64-gnu-llvm-14` (one of the PR builders) to use 3.11.

While fixing that, I noticed that we stopped testing python2.7 support on PR CI in rust-lang#106085. `@fee1-dead` `@pietroalbini` please be more careful in the future, there is no CI for CI itself that verifies we are testing everything we should be.

- Separate out functions so that each unit test doesn't create a file on disk
- Add a few unit tests

…ray_windows, r=scottmcm

Make `slice::is_sorted_by` implementation nicer

Just tweak implementation a little :)

r? `@thomcc`

…er-errors

Fix generics_of for impl's RPITIT synthesized associated type

The only useful commit is the last one.

This makes `generics_of` for the impl side RPITIT copy from the trait's associated type and avoid the fn on the impl side which was previously wrongly used.
This solution is better but we still need to fix resolution of the generated generics.

r? ``@compiler-errors``

…er-errors

Ignore `Inlined` spans when computing caller location.

Fixes rust-lang#105538

…oxyUwU

Only expect a GAT const param for `type_of` of GAT const arg

IDK why we were account for both `is_ty_or_const` instead of just for a const param, since we're computing the `type_of` a const param specifically.

Fixes rust-lang#109300

…crum

Update mdbook

This updates mdbook from 0.4.25 to 0.4.28.
Changelog: https://github.com/rust-lang/mdBook/blob/master/CHANGELOG.md#mdbook-0428

The primary changes are some interaction fixes for Mobile Safari and removing custom scrollbars on webkit browsers, along with a few other fixes.