Set the default BreakTy to !

Author: LeSeulArtichaut

clippy_lints/src/redundant_clone.rs

@@ -563,6 +563,8 @@ impl<'a, 'tcx> mir::visit::Visitor<'tcx> for PossibleBorrowerVisitor<'a, 'tcx> {
 struct ContainsRegion;
 
 impl TypeVisitor<'_> for ContainsRegion {
+    type BreakTy = ();
+
     fn visit_region(&mut self, _: ty::Region<'_>) -> ControlFlow<Self::BreakTy> {
         ControlFlow::BREAK
     }