Such implementations are usually mistakes and are not used in the
compiler or standard library (after this commit) so forbid them with
`min_specialization`.
Improve check-cfg implementation
This PR makes multiple improvements into the implementation of check-cfg, it is a prerequisite to a follow-up PR that will introduce a simpler and more explicit syntax.
The 2 main area of improvements are:
1. Internal representation of expected values:
- now uses `FxHashSet<Option<Symbol>>` instead of `FxHashSet<Symbol>`, it made the no value expected case only possible when no values where in the `HashSet` which is now represented as `None` (same as cfg represent-it).
- a enum with `Some` and `Any` makes it now clear if some values are expected or not, necessary for `feature` and `target_feature`.
2. Diagnostics: Improve the diagnostics in multiple case and fix case where a missing value could have had a new name suggestion instead of the value diagnostic; and some drive by improvements
I highly recommend reviewing commit by commit.
r? `@petrochenkov`
Added default target cpu to `--print target-cpus` output and updated docs
Added default target cpu info as requested in issue #110647 and noted the new output in the documentation
This is done to simplify to relationship between names() and values()
but also make thing clearer (having an Any to represent that any values
are allowed) but also to allow the (none) + values expected cases that
wasn't possible before.
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).
check array type of repeat exprs is wf
Fixes#111091
Also makes sure that we actually renumber regions in the length of repeat exprs which we previously weren't doing and would cause ICEs in `adt_const_params` + `generic_const_exprs` from attempting to prove the wf goals when the length was an unevaluated constant with `'erased` in the `ty` field of `Const`
The duplicate errors are caused by the fact that `const_arg_to_const`/`array_len_to_const` in `FnCtxt` adds a `WellFormed` goal for the created `Const` which is also checked by the added `WellFormed(array_ty)`. I don't want to change this to just emit a `T: Sized` goal for the element type since that would ignore `ConstArgHasType` wf requirements and generally uncomfortable with the idea of trying to sync up `wf::obligations` for arrays and the code in hir typeck for repeat exprs.
r? `@compiler-errors`
