Rollup merge of #106525 - compiler-errors:new-solver-wf, r=jackh726

Report WF error for chalk *and* new solver

addressing this nit #106385 (comment)

No test yet because new solver is currently unusable, lol

r? `@lcnr`

Author: compiler-errors

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -1168,7 +1168,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     }
 
                     ty::PredicateKind::WellFormed(ty) => {
-                        if self.tcx.sess.opts.unstable_opts.trait_solver != TraitSolver::Chalk {
+                        if self.tcx.sess.opts.unstable_opts.trait_solver == TraitSolver::Classic {
                             // WF predicates cannot themselves make
                             // errors. They can only block due to
                             // ambiguity; otherwise, they always
@@ -1180,7 +1180,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             // which bounds actually failed to hold.
                             self.tcx.sess.struct_span_err(
                                 span,
-                                &format!("the type `{}` is not well-formed (chalk)", ty),
+                                &format!("the type `{}` is not well-formed", ty),
                             )
                         }
                     }

src/test/ui/chalkify/recursive_where_clause_on_type.rs

@@ -25,6 +25,6 @@ fn foo<T: Foo>() {
 fn main() {
     // For some reason, the error is duplicated...
 
-    foo::<S>() //~ ERROR the type `S` is not well-formed (chalk)
-    //~^ ERROR the type `S` is not well-formed (chalk)
+    foo::<S>() //~ ERROR the type `S` is not well-formed
+    //~^ ERROR the type `S` is not well-formed
 }

src/test/ui/chalkify/recursive_where_clause_on_type.stderr

@@ -1,10 +1,10 @@
-error: the type `S` is not well-formed (chalk)
+error: the type `S` is not well-formed
   --> $DIR/recursive_where_clause_on_type.rs:28:11
    |
 LL |     foo::<S>()
    |           ^
 
-error: the type `S` is not well-formed (chalk)
+error: the type `S` is not well-formed
   --> $DIR/recursive_where_clause_on_type.rs:28:5
    |
 LL |     foo::<S>()