Prevent removal of qualified path for tuple struct inside macro

fixes 5005

This was very similar to 4964 and the fix was to extract and pass along
the qself of the ``PatKind::TupleStruct``

src/patterns.rs

@@ -226,8 +226,9 @@ impl Rewrite for Pat {
             PatKind::Path(ref q_self, ref path) => {
                 rewrite_path(context, PathContext::Expr, q_self.as_ref(), path, shape)
             }
-            PatKind::TupleStruct(_, ref path, ref pat_vec) => {
-                let path_str = rewrite_path(context, PathContext::Expr, None, path, shape)?;
+            PatKind::TupleStruct(ref q_self, ref path, ref pat_vec) => {
+                let path_str =
+                    rewrite_path(context, PathContext::Expr, q_self.as_ref(), path, shape)?;
                 rewrite_tuple_pat(pat_vec, Some(path_str), self.span, context, shape)
             }
             PatKind::Lit(ref expr) => expr.rewrite(context, shape),

tests/target/issue-5005/minimum_example.rs

@@ -0,0 +1,9 @@
+#![feature(more_qualified_paths)]
+macro_rules! show {
+    ($ty:ty, $ex:expr) => {
+        match $ex {
+            <$ty>::A(_val) => println!("got a"), // formatting should not remove <$ty>::
+            <$ty>::B => println!("got b"),
+        }
+    };
+}