Auto merge of rust-lang#99806 - oli-obk:unconstrained_opaque_type, r=…

…estebank

Allow patterns to constrain the hidden type of opaque types

fixes rust-lang#96572

reverts a revert as original PR was a perf regression that was fixed by reverting it: rust-lang#99368 (comment))

TODO:

* check if rust-lang#99685 is avoided

clippy_utils/src/qualify_min_const_fn.rs

@@ -260,6 +260,7 @@ fn check_place<'tcx>(tcx: TyCtxt<'tcx>, place: Place<'tcx>, span: Span, body: &B
                 }
             },
             ProjectionElem::ConstantIndex { .. }
+            | ProjectionElem::OpaqueCast(..)
             | ProjectionElem::Downcast(..)
             | ProjectionElem::Subslice { .. }
             | ProjectionElem::Deref