Fix stack overflow when derefrencing &!

crates/ide-diagnostics/src/handlers/mutability_errors.rs

@@ -336,6 +336,18 @@ fn main() {
         );
     }
 
+    #[test]
+    fn regression_14310() {
+        check_diagnostics(
+            r#"
+            fn clone(mut i: &!) -> ! {
+                   //^^^^^ 💡 weak: variable does not need to be mutable
+                *i
+            }
+        "#,
+        );
+    }
+
     #[test]
     fn match_bindings() {
         check_diagnostics(