Auto merge of #144458 - compiler-errors:no-witness-mini, r=lcnr

Remove the witness type from coroutine *args* (without actually removing the type)

This does as much of rust-lang/rust#144157 as we can without having to break rust-lang/rust#143545 and/or introduce some better way of handling higher ranked assumptions.

Namely, it:
* Stalls coroutines based off of the *coroutine* type rather than the witness type.
* Reworks the dtorck constraint hack to not rely on the witness type.
* Removes the witness type from the args of the coroutine, eagerly creating the type for nested obligations when needed (auto/clone impls).

I'll experiment with actually removing the witness type in a follow-up.

r? lcnr

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -355,7 +355,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for StalledOnCoroutines<'tcx> {
             return ControlFlow::Continue(());
         }
 
-        if let ty::CoroutineWitness(def_id, _) = *ty.kind()
+        if let ty::Coroutine(def_id, _) = *ty.kind()
             && def_id.as_local().is_some_and(|def_id| self.stalled_coroutines.contains(&def_id))
         {
             ControlFlow::Break(())