Implement RFC3695 Allow boolean literals as cfg predicates
This PR implements https://github.com/rust-lang/rfcs/pull/3695: allow boolean literals as cfg predicates, i.e. `cfg(true)` and `cfg(false)`.
r? `@nnethercote` *(or anyone with parser knowledge)*
cc `@clubby789`
remove blank issue template
r? `@Noratrieb`
So there are currently two blank issue templates. One called "Blank Issue" and one called "Blank issue". Wildly different, of course. It seems that one is auto generated by GitHub, while the other one has an explicit template for it. This removes the explicit one so there's only one "Blank [iI]ssue" in the list. Unfortunately, the only way to test if it works is merging this and finding out, but it seems obvious that it would work.

The `regioncx` and `borrow_set` fields can be references instead of
`Rc`. They use the existing `'a` lifetime. This avoids some heap
allocations and is a bit simpler.
Disable jump threading `UnOp::Not` for non-bool
Fix#131195, where jumpthreading was optimizing `!a == b` into `a != b` for non-bool, where this is definitely not true.
what matters is we re doing the right things as doing sizeof, rather than
KINFO_FILE_SIZE (only defined on intel architectures), the kernel
making sure it matches the expectation in its side.
Compare trait references in `trait_duplication_in_bounds` correctly
Fixes#13476Fixes#11067Fixes#9915Fixes#9626
Currently, the `trait_duplication_in_bounds` lints has a helper type for a trait reference that can be used for comparison and hashing, represented as `{trait: Res, generic_args: Vec<Res>}`. However, there are a lot of issues with this. For one, a `Res` can't represent e.g. references, slices, or lots of other types, as well as const generics and associated type equality. In those cases, the lint simply ignores them and has no way of checking if they're actually the same.
So, instead of using `Res` for this, use `SpanlessEq` and `SpanlessHash` for comparisons with the trait path for checking if there are duplicates.
However, using `SpanlessEq` as is alone lead to a false negative in the test. `std::clone::Clone` + `foo::Clone` wasn't recognized as a duplicate, because it has different segments. So this also adds a new "mode" to SpanlessEq which compares by final resolution. (I've been wondering if this can't just be the default but it's quite a large scale change as it affects a lot of lints and I haven't yet looked at all uses of it to see if there are lints that really do care about having exactly the same path segments).
Maybe an alternative would be to turn the hir types/consts into middle types/consts and compare them instead but I'm not sure there's really a good way to do that
changelog: none
Most of the code in these two modules is duplicated in the other module.
This commit eliminates the duplication by replacing them with a new
module `lattice_op`. The new `LatticeOpKind` enum is used to distinguish
between glb and lub in the few places where the behaviour differs.
Avoid emptiness check in `PeekMut::pop`
This PR avoids an unnecessary emptiness check in `PeekMut::pop` by replacing `Option::unwrap` with `Option::unwrap_unchecked`.
Refactoring to `OpaqueTyOrigin`
Pulled out of a larger PR that uses these changes to do cross-crate encoding of opaque origin, so we can use them for edition 2024 migrations. These changes should be self-explanatory on their own, tho 😄
Avoid ICE in coverage builds with bad `#[coverage(..)]` attributes
This code can sometimes witness malformed coverage attributes in builds that are going to fail, so use `span_delayed_bug` to avoid an inappropriate ICE in that case.
Fixes#127880.
Refactoring to `OpaqueTyOrigin`
Pulled out of a larger PR that uses these changes to do cross-crate encoding of opaque origin, so we can use them for edition 2024 migrations. These changes should be self-explanatory on their own, tho 😄
.gitignore files for nix
This adds support for direnv and nix flakes / nix shell. I'm not sure if we should have a working nix configuration though.
r? ``@noratrieb``
Don't give method suggestions when method probe fails due to bad implementation of `Deref`
If we have a bad `Deref` impl, we used to bail with `MethodError::NoMatch`, which makes the error reporting code think that there was no applicable method (and thus try to suggest importing something, even if it's in scope).
Suppress this error, which fixes#131003.