Add more tests

Author: Nadrieril

tests/ui/rfcs/rfc-0000-never_patterns/bindings.rs

@@ -23,3 +23,13 @@ fn main() {
         //~| ERROR: never patterns cannot contain variable bindings
     }
 }
+
+fn void(void: Void) {
+    let (_a | !) = void;
+    let (! | _a) = void;
+    let ((_a, _) | (_a, _ | !)) = (true, void);
+    let (_a, (! | !)) = (true, void);
+    //~^ ERROR: never patterns cannot contain variable bindings
+    let (_a | (! | !,)) = (void,);
+    let ((_a,) | (!,)) = (void,);
+}

tests/ui/rfcs/rfc-0000-never_patterns/bindings.stderr

@@ -22,5 +22,11 @@ error: never patterns cannot contain variable bindings
 LL |         Ok(_ok) | Err(&(_a, _b, !)) => {}
    |                             ^^ help: use a wildcard `_` instead
 
-error: aborting due to 4 previous errors
+error: never patterns cannot contain variable bindings
+  --> $DIR/bindings.rs:31:10
+   |
+LL |     let (_a, (! | !)) = (true, void);
+   |          ^^ help: use a wildcard `_` instead
+
+error: aborting due to 5 previous errors