style: Track the visited-handling-mode on the MatchingContext.

Instead of on the stack.

This fixes bugs where we're not passing the value around correctly, like from
::-moz-any.

This is a fix for https://bugzilla.mozilla.org/show_bug.cgi?id=1431539.

components/style/stylist.rs

@@ -1246,7 +1246,7 @@ impl Stylist {
             // Step 2: Presentational hints.
             let length_before_preshints = applicable_declarations.len();
             element.synthesize_presentational_hints_for_legacy_attributes(
-                context.visited_handling,
+                context.visited_handling(),
                 applicable_declarations
             );
             if applicable_declarations.len() != length_before_preshints {