…oalbini

Support loading version information from xz tarballs

This is intended to allow us to move recompression from xz (produced in CI) to gz after an initial manifest run, which produces a list of actually required artifacts. The rest are then deleted, which means that we can avoid recompressing them, saving a bunch of time.

This is essentially untested and more might be needed, will run a patched promote-release against try artifacts from this PR. If we do go ahead with this we'll either need to backport this patch to beta/stable, wait for it to propagate, or temporarily recompress to gzip but not xz tarballs (or similar).

r? `@pietroalbini`

Implement negative bounds for internal testing purposes

Implements partial support the `!` negative polarity on trait bounds. This is incomplete, but should allow us to at least be able to play with the feature.

Not even gonna consider them as a public-facing feature, but I'm implementing them because would've been nice to have in UI tests, for example in #110671.

Adjust obligation cause code for `find_and_report_unsatisfied_index_impl`

Makes the error message a bit easier to read.

resolve: One more attempt to simplify `module_children`

If the next step is performed and `fn module_children_local` is merged with the `module_children` query, then it causes perf regressions, regardless of whether query result feeding is [used](https://perf.rust-lang.org/compare.html?start=43a78029b4f4d92978b8fde0a677ea300b113c41&end=2eb5bcc5068b9d92f74bcb1797da664865d6981d&stat=instructions:u) or [not](https://perf.rust-lang.org/compare.html?start=2fce2290865f012391b8f3e581c3852a248031fa&end=2a33d6cd99481d1712037a79e7d66a8aefadbf72&stat=instructions:u).

interpret: fail more gracefully on uninit unsized locals

r? `@oli-obk`

Fixes rust-lang/rust#68538

…enkov

Don't bail out early when checking invalid `repr` attr

Fixes #111051

An invalid repr delays a bug. If there are other invalid attributes on the item, we emit a warning and exit without re-checking the repr here, so no error is emitted and the delayed bug ICEs

…arsan68

remove pointless `FIXME` in `bootstrap::download`

The suggestion given by `FIXME` to use `CompilerMetadata` for `download_toolchain` in `bootstrap::download` can result in more confusion. This is because `stamp_key` is not always a date; it can also be a commit hash. Additionally, unlike in `download_beta_toolchain`, in the `download_ci_rustc` function, `version` and `commit` values are calculated separately.

Remove `MemEncoder`

`MemEncoder` only has one non-test use, and `FileEncoder` would be more appropriate there anyway.

r? ``@cjgillot``

Avoid ICEing miri on layout query cycles

Miri has special logic for catching panics during interpretation. Raising a fatal error in rustc uses unwinding to abort compilation. Thus miri ends up catching that fatal error and thinks it saw an ICE. While we should probably change that to ignore `Fatal` payloads, I think it's also neat to continue compilation after a layout query cycle 😆

Query cycles now (in addition to reporting an error just like before), return `Err(Cycle)` instead of raising a fatal error. This allows the interpreter to wind down via the regular error paths.

r? `@RalfJung` for a first round, feel free to reroll for the compiler team once the miri side looks good

Add some triagebot notifications for nnethercote.

r? ````@compiler-errors````

Rollup of 11 pull requests

Successful merges:

 - #107978 (Correctly convert an NT path to a Win32 path in `read_link`)
 - #110436 (Support loading version information from xz tarballs)
 - #110791 (Implement negative bounds for internal testing purposes)
 - #110874 (Adjust obligation cause code for `find_and_report_unsatisfied_index_impl`)
 - #110908 (resolve: One more attempt to simplify `module_children`)
 - #110943 (interpret: fail more gracefully on uninit unsized locals)
 - #111062 (Don't bail out early when checking invalid `repr` attr)
 - #111069 (remove pointless `FIXME` in `bootstrap::download`)
 - #111086 (Remove `MemEncoder`)
 - #111097 (Avoid ICEing miri on layout query cycles)
 - #111112 (Add some triagebot notifications for nnethercote.)

Failed merges:

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

Return error code from x.ps1

Fixes #111136

This works around a bug where `ExitCode` does not return the exit code. See: https://stackoverflow.com/a/23797762

Replace `tcx.mk_trait_ref` with `TraitRef::new`

First step in implementing rust-lang/compiler-team#616
r? `@lcnr`

try to downgrade Arc -> Lrc -> Rc -> no-Rc in few places

Expecting this be not slower on non-parallel compiler and probably faster on parallel (checked that this PR builds on it).