Auto merge of #82249 - JohnTitor:rollup-3jbqija, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #82055 (Add diagnostics for specific cases for const/type mismatch err)
 - #82155 (Use !Sync std::lazy::OnceCell in usefulness checking)
 - #82202 (add specs for riscv32/riscv64 musl targets)
 - #82203 (Move some tests to more reasonable directories - 4)
 - #82211 (make `suggest_setup` help messages better)
 - #82212 (Remove redundant rustc_data_structures path component)
 - #82240 (remove useless ?s (clippy::needless_question_marks))
 - #82243 (Add more intra-doc links to std::io)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs

@@ -43,7 +43,7 @@ where
             info!("fully_perform({:?})", self);
         }
 
-        scrape_region_constraints(infcx, || Ok((self.closure)(infcx)?))
+        scrape_region_constraints(infcx, || (self.closure)(infcx))
     }
 }