Removed deprected ui/enum-representation/internally-tagged-struct test

test_suite/tests/ui/enum-representation/internally-tagged-struct.rs

@@ -1,8 +0,0 @@
-#[macro_use]
-extern crate serde_derive;
-
-#[derive(Serialize)]
-#[serde(tag = "type")]
-struct S;
-
-fn main() {}

test_suite/tests/ui/enum-representation/internally-tagged-struct.stderr

@@ -1,8 +0,0 @@
-error: #[serde(tag = "...")] can only be used on enums
- --> $DIR/internally-tagged-struct.rs:6:1
-  |
-6 | struct S;
-  | ^^^^^^
-
-error: aborting due to previous error
-