Rollup merge of #110631 - notriddle:notriddle/impl-trait-cycle, r=GuillaumeGomez

rustdoc: catch and don't blow up on impl Trait cycles

Fixes #110629

An odd feature of Rust is that `Foo` is invalid, but `Bar` is okay:

    type Foo<'a, 'b> = Box<dyn PartialEq<Foo<'a, 'b>>>;
    type Bar<'a, 'b> = impl PartialEq<Bar<'a, 'b>>;

To get it right, track every time rustdoc descends into a type alias, so if it shows up twice, it can be write the path instead of infinitely expanding it.

0 files changed, 0 insertions, 0 deletions