Update pretty test for derive attributes

Remove attr-variant-data.rs since it relies on quirks
in legacy custom derive resolution (undefined derives
only print a warning).

Add a new test which uses a defined proc macro derive,
and tests pretty printing of proc macro derive
attributes.

Author: keeperofdakeys

src/test/pretty/attr-derive.rs

@@ -0,0 +1,43 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// aux-build:derive-foo.rs
+// ignore-stage1
+// pp-exact
+// Testing that both the inner item and next outer item are
+// preserved, and that the first outer item parsed in main is not
+// accidentally carried over to each inner function
+
+#[macro_use]
+extern crate derive_foo;
+
+#[derive(Foo)]
+struct X;
+
+#[derive(Foo)]
+#[Bar]
+struct Y;
+
+#[derive(Foo)]
+struct WithRef {
+    x: X,
+    #[Bar]
+    y: Y,
+}
+
+#[derive(Foo)]
+enum Enum {
+
+    #[Bar]
+    Asdf,
+    Qwerty,
+}
+
+fn main() { }

src/test/pretty/attr-variant-data.rs

@@ -0,0 +1,22 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+
+#[proc_macro_derive(Foo, attributes(Bar))]
+pub fn derive(input: TokenStream) -> TokenStream {
+    "".parse().unwrap()
+}