resolve: Introduce two sub-namespaces in macro namespace

src/test/ui-fulldeps/proc-macro/auxiliary/derive-helper-shadowed-2.rs

@@ -0,0 +1,2 @@
+#[macro_export]
+macro_rules! my_attr { () => () }

src/test/ui-fulldeps/proc-macro/auxiliary/derive-helper-shadowed.rs

@@ -0,0 +1,11 @@
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::*;
+
+#[proc_macro_derive(MyTrait, attributes(my_attr))]
+pub fn foo(_: TokenStream) -> TokenStream {
+    TokenStream::new()
+}

src/test/ui-fulldeps/proc-macro/derive-helper-shadowed.rs

@@ -0,0 +1,16 @@
+// compile-pass
+// aux-build:derive-helper-shadowed.rs
+// aux-build:derive-helper-shadowed-2.rs
+
+#[macro_use]
+extern crate derive_helper_shadowed;
+#[macro_use(my_attr)]
+extern crate derive_helper_shadowed_2;
+
+macro_rules! my_attr { () => () }
+
+#[derive(MyTrait)]
+#[my_attr] // OK
+struct S;
+
+fn main() {}

src/test/ui/issues/issue-11692-2.rs

@@ -9,5 +9,5 @@
 // except according to those terms.
 
 fn main() {
-    concat!(test!()); //~ ERROR `test` can only be used in attributes
+    concat!(test!()); //~ ERROR cannot find macro `test!` in this scope
 }

src/test/ui/issues/issue-11692-2.stderr

@@ -1,7 +1,7 @@
-error: `test` can only be used in attributes
+error: cannot find macro `test!` in this scope
   --> $DIR/issue-11692-2.rs:12:13
    |
-LL |     concat!(test!()); //~ ERROR `test` can only be used in attributes
+LL |     concat!(test!()); //~ ERROR cannot find macro `test!` in this scope
    |             ^^^^
 
 error: aborting due to previous error

src/test/ui/macros/macro-path-prelude-fail-3.rs

@@ -1,16 +1,3 @@
-// Copyright 2018 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.
-
-#[derive(inline)] //~ ERROR cannot find derive macro `inline` in this scope
-struct S;
-
 fn main() {
     inline!(); //~ ERROR cannot find macro `inline!` in this scope
 }

src/test/ui/macros/macro-path-prelude-fail-3.stderr

@@ -1,14 +1,8 @@
-error: cannot find derive macro `inline` in this scope
-  --> $DIR/macro-path-prelude-fail-3.rs:11:10
-   |
-LL | #[derive(inline)] //~ ERROR cannot find derive macro `inline` in this scope
-   |          ^^^^^^
-
 error: cannot find macro `inline!` in this scope
-  --> $DIR/macro-path-prelude-fail-3.rs:15:5
+  --> $DIR/macro-path-prelude-fail-3.rs:2:5
    |
 LL |     inline!(); //~ ERROR cannot find macro `inline!` in this scope
    |     ^^^^^^ help: you could try the macro: `line`
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 

src/test/ui/macros/macro-path-prelude-fail-4.rs

@@ -0,0 +1,4 @@
+#[derive(inline)] //~ ERROR expected a macro, found built-in attribute
+struct S;
+
+fn main() {}

src/test/ui/macros/macro-path-prelude-fail-4.stderr

@@ -0,0 +1,8 @@
+error: expected a macro, found built-in attribute
+  --> $DIR/macro-path-prelude-fail-4.rs:1:10
+   |
+LL | #[derive(inline)] //~ ERROR expected a macro, found built-in attribute
+   |          ^^^^^^
+
+error: aborting due to previous error
+