Centralize box pattern tests in patterns.rs

Author: ecstatic-morse

crates/ra_parser/src/grammar/expressions/atom.rs

@@ -414,8 +414,6 @@ pub(crate) fn match_arm_list(p: &mut Parser) {
 //         X | Y if Z => (),
 //         | X | Y if Z => (),
 //         | X => (),
-//         box X => (),
-//         Some(box X) => (),
 //     };
 // }
 fn match_arm(p: &mut Parser) -> BlockLike {

crates/ra_parser/src/grammar/patterns.rs

@@ -269,11 +269,6 @@ fn bind_pat(p: &mut Parser, with_at: bool) -> CompletedMarker {
     m.complete(p, BIND_PAT)
 }
 
-// test_err ref_box_pat
-// fn main() {
-//     let ref box i = ();
-// }
-
 // test box_pat
 // fn main() {
 //     let box i = ();

crates/ra_syntax/test_data/parser/err/0034_bad_box_pattern.rs

@@ -0,0 +1,6 @@
+fn main() {
+    let ref box i = ();
+    let mut box i = ();
+    let ref mut box i = ();
+}
+