This commit makes two changes - separating the `NodeId` that identifies
an enum variant from the `NodeId` that identifies the variant's
constructor; and no longer creating a `NodeId` for `Struct`-style enum
variants and structs.
Separation of the variant id and variant constructor id will allow the
rest of RFC 2008 to be implemented by lowering the visibility of the
variant's constructor without lowering the visbility of the variant
itself.
No longer creating a `NodeId` for `Struct`-style enum variants and
structs mostly simplifies logic as previously this `NodeId` wasn't used.
There were various cases where the `NodeId` wouldn't be used unless
there was an unit or tuple struct or enum variant but not all uses of
this `NodeId` had that condition, by removing this `NodeId`, this must
be explicitly dealt with. This change mostly applied cleanly, but there
were one or two cases in name resolution and one case in type check
where the existing logic required a id for `Struct`-style enum variants
and structs.
Add const generics to rustdoc
Split out from #53645. This work is a collaborative effort with @yodaldevoid.
The `FIXME`s are waiting on a refactor to `LazyConst`. I'll address these in a follow up, but I thought it would be better to implement the rest now to avoid bitrot.
r? @QuietMisdreavus
Revert the `LazyConst` PR
The introduction of `LazyConst` did not actually achieve the code simplicity improvements that were the main reason it was introduced. Especially in the presence of const generics, the differences between the "levels of evaluatedness" of a constant become less clear. As it can be seen by the changes in this PR, further simplifications were possible by folding `LazyConst` back into `ConstValue`. We have been able to keep all the advantages gained during the `LazyConst` refactoring (like `const_eval` not returning an interned value, thus making all the `match` code simpler and more performant).
fixes https://github.com/rust-lang/rust/issues/59209
r? @eddyb @varkor
