Start working on a test

Author: mark-i-m

src/test/ui/anon-params-denied-2018.rs

@@ -0,0 +1,13 @@
+// Test that anonymous parameters are disallowed in 2018 edition.
+
+// edition:2018
+
+trait T {
+    fn foo(i32); //~ ERROR expected identifier
+
+    fn bar_with_default_impl(String, String) {}
+    //~^ ERROR expected identifier
+    //~| ERROR expected identifier
+}
+
+fn main() {}