Clean up and add extra tests

src/test/ui/E0642.rs

@@ -8,12 +8,17 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-trait Foo {
-    fn foo((x, y): (i32, i32)); //~ ERROR patterns aren't allowed in trait methods
-}
+#[derive(Clone, Copy)]
+struct S;
 
-trait Bar {
-    fn bar((x, y): (i32, i32)) {} //~ ERROR patterns aren't allowed in trait methods
+trait T {
+    fn foo((x, y): (i32, i32)); //~ ERROR patterns aren't allowed in methods without bodies
+
+    fn bar((x, y): (i32, i32)) {} //~ ERROR patterns aren't allowed in methods without bodies
+
+    fn f(&ident: &S) {} // ok
+    fn g(&&ident: &&S) {} // ok
+    fn h(mut ident: S) {} // ok
 }
 
 fn main() {}

src/test/ui/E0642.stderr

@@ -1,21 +1,21 @@
-error[E0642]: patterns aren't allowed in trait methods
-  --> $DIR/E0642.rs:12:12
+error[E0642]: patterns aren't allowed in methods without bodies
+  --> $DIR/E0642.rs:15:12
    |
-LL |     fn foo((x, y): (i32, i32)); //~ ERROR patterns aren't allowed in trait methods
+LL |     fn foo((x, y): (i32, i32)); //~ ERROR patterns aren't allowed in methods without bodies
    |            ^^^^^^
 help: give this argument a name or use an underscore to ignore it
    |
-LL |     fn foo(_: (i32, i32)); //~ ERROR patterns aren't allowed in trait methods
+LL |     fn foo(_: (i32, i32)); //~ ERROR patterns aren't allowed in methods without bodies
    |            ^
 
-error[E0642]: patterns aren't allowed in trait methods
-  --> $DIR/E0642.rs:16:12
+error[E0642]: patterns aren't allowed in methods without bodies
+  --> $DIR/E0642.rs:17:12
    |
-LL |     fn bar((x, y): (i32, i32)) {} //~ ERROR patterns aren't allowed in trait methods
+LL |     fn bar((x, y): (i32, i32)) {} //~ ERROR patterns aren't allowed in methods without bodies
    |            ^^^^^^
 help: give this argument a name or use an underscore to ignore it
    |
-LL |     fn bar(_: (i32, i32)) {} //~ ERROR patterns aren't allowed in trait methods
+LL |     fn bar(_: (i32, i32)) {} //~ ERROR patterns aren't allowed in methods without bodies
    |            ^
 
 error: aborting due to 2 previous errors