Add more tests

Author: Nadrieril

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

@@ -23,3 +23,24 @@ 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 | (! | !,)) = (void,);
+    let ((_a,) | (!,)) = (void,);
+
+    let (_a, (! | !)) = (true, void);
+    //~^ ERROR: never patterns cannot contain variable bindings
+    let (_a, (_b | !)) = (true, void);
+
+    let _a @ ! = void;
+    //~^ ERROR: never patterns cannot contain variable bindings
+    let _a @ (_b | !) = void;
+    let (_a @ (), !) = ((), void);
+    //~^ ERROR: never patterns cannot contain variable bindings
+    let (_a |
+            (_b @ (_, !))) = (true, void);
+    //~^ ERROR: never patterns cannot contain variable bindings
+}

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

@@ -22,5 +22,29 @@ 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:34:10
+   |
+LL |     let (_a, (! | !)) = (true, void);
+   |          ^^ help: use a wildcard `_` instead
+
+error: never patterns cannot contain variable bindings
+  --> $DIR/bindings.rs:38:9
+   |
+LL |     let _a @ ! = void;
+   |         ^^ help: use a wildcard `_` instead
+
+error: never patterns cannot contain variable bindings
+  --> $DIR/bindings.rs:41:10
+   |
+LL |     let (_a @ (), !) = ((), void);
+   |          ^^ help: use a wildcard `_` instead
+
+error: never patterns cannot contain variable bindings
+  --> $DIR/bindings.rs:44:14
+   |
+LL |             (_b @ (_, !))) = (true, void);
+   |              ^^ help: use a wildcard `_` instead
+
+error: aborting due to 8 previous errors