Emit a note that static bounds from HRTBs are a bug
This note isn't perfect, but opening this to either 1) land as is or 2) get some feedback on how to improve it
Let r? `@compiler-errors` and cc. `@nikomatsakis`
Add support for MIPS VZ ISA extension
[Link to relevant LLVM line where virt extension is specified](83fab8cee9/llvm/lib/Target/Mips/Mips.td (L172-L173))
This has been tested on mips-unknown-linux-musl with a target-cpu that is >= MIPS32 5 and `target-features=+virt`. The example was checked in a disassembler to ensure the correct assembly sequence was being generated using the virtualization instructions.
Needed additional work:
* MIPS is missing from [the Rust reference CPU feature lists](https://doc.rust-lang.org/reference/attributes/codegen.html#available-features)
Example docs for later:
```md
#### `mips` or `mips64`
This platform requires that `#[target_feature]` is only applied to [`unsafe`
functions][unsafe function]. This target's feature support is currently unstable
and must be enabled by `#![feature(mips_target_feature)]` ([Issue #44839])
[Issue #44839]: https://github.com/rust-lang/rust/issues/44839
Further documentation on these features can be found in the [MIPS Instruction Set
Reference Manual], or elsewhere on [mips.com].
[MIPS Instruction Set Reference Manual]: https://s3-eu-west-1.amazonaws.com/downloads-mips/documents/MD00086-2B-MIPS32BIS-AFP-6.06.pdf
[developer.arm.com]: https://www.mips.com/products/architectures/ase/
Feature | Implicitly Enables | Description
---------------|--------------------|-------------------
`fp64` | | 64-bit Floating Point
`msa` | | "MIPS SIMD Architecture"
`virt` | | Virtualization instructions (VZ ASE)
```
If the above is good I can also submit a PR for that if there's interest in documenting it while it's still unstable. Otherwise that can be dropped, I just wrote it before realizing it was possibly not a good idea.
Relevant to #44839
Simplify caching and storage for queries
I highly recommend reviewing commit-by-commit; each individual commit is quite small but it can be hard to see looking at the overall diff that the behavior is the same. Each commit depends on the previous.
r? `@cjgillot`
Make `compare_predicate_entailment` no longer a query
Make `compare_predicate_entailment` so it's no longer a query (again), and splits out the new logic (that equates the return types to infer RPITITs) into its own query. This means that this new query (now called `collect_trait_impl_trait_tys`) is no longer executed for non-RPITIT cases.
This should improve perf (https://github.com/rust-lang/rust/pull/101224#issuecomment-1241682203), though in practice we see that these some crates remain from the primary regressions list on the original report... They are all <= 0.43% regression and seemingly only on the incr-full scenario for all of them.
I am at a loss for what might be causing this regression other than what I fixed here, since we don't introduce much new non-RPITIT logic except for some `def_kind` query calls in some places, for example, like projection. Maybe that's it?
----
Originally this PR was opened to test enabling `cache_on_disk` (62164aaaa11) but that didn't turn out to be very useful (https://github.com/rust-lang/rust/pull/101615#issuecomment-1242403205), so that led me to just split the query (and rename the PR).
