Auto merge of #115429 - compiler-errors:assoc-ct-lt-fallthrough, r=cjgillot

Fall through when resolving elided assoc const lifetimes

`@QuineDot` makes a good point in rust-lang/rust#115010 (comment) that we probably should not accept *more* code due to #115011 even though that code will eventually become a forbid-warning in a few versions (rust-lang/rust#115010 (comment)).

Fall through when walking thru the `AnonymousWarnToStatic` (renamed to `AnonymousWarn`) rib so that we can resolve as a fresh lifetime like we did before.

Author: bors