add aux-crates to test

Author: Qelxiros

tests/ui/typeck/auxiliary/private-dep.rs

@@ -0,0 +1,3 @@
+pub trait A {
+    fn foo() {}
+}

tests/ui/typeck/auxiliary/public-dep.rs

@@ -0,0 +1,11 @@
+//@ aux-crate:priv:private_dep=private-dep.rs
+//@ compile-flags: -Zunstable-options
+
+extern crate private_dep;
+use private_dep::A;
+
+pub struct B;
+
+impl A for B {
+    fn foo() {}
+}

tests/ui/typeck/dont-suggest-private-dependencies.rs

@@ -5,6 +5,11 @@
 //@ forbid-output: compiler_builtins
 //@ forbid-output: object
 
+// Check a custom trait to withstand changes in above crates
+//@ aux-crate:public_dep=public-dep.rs
+//@ compile-flags: -Zunstable-options
+//@ forbid-output: private_dep
+
 struct VecReader(Vec<u8>);
 
 impl std::io::Read for VecReader {
@@ -14,7 +19,12 @@ impl std::io::Read for VecReader {
     }
 }
 
+extern crate public_dep;
+use public_dep::B;
+
 fn main() {
     let _ = u8::cast_from_lossy(9);
     //~^ ERROR no function or associated item named `cast_from_lossy` found for type `u8`
+    let _ = B::foo();
+    //~^ ERROR no function or associated item named `foo` found for struct `B`
 }

tests/ui/typeck/dont-suggest-private-dependencies.stderr

@@ -1,5 +1,5 @@
 error[E0599]: no method named `read` found for struct `Vec<u8>` in the current scope
-  --> $DIR/dont-suggest-private-dependencies.rs:12:16
+  --> $DIR/dont-suggest-private-dependencies.rs:17:16
    |
 LL |         self.0.read(buf)
    |                ^^^^
@@ -10,11 +10,17 @@ LL |         self.0.read_at(buf)
    |                    +++
 
 error[E0599]: no function or associated item named `cast_from_lossy` found for type `u8` in the current scope
-  --> $DIR/dont-suggest-private-dependencies.rs:18:17
+  --> $DIR/dont-suggest-private-dependencies.rs:26:17
    |
 LL |     let _ = u8::cast_from_lossy(9);
    |                 ^^^^^^^^^^^^^^^ function or associated item not found in `u8`
 
-error: aborting due to 2 previous errors
+error[E0599]: no function or associated item named `foo` found for struct `B` in the current scope
+  --> $DIR/dont-suggest-private-dependencies.rs:28:16
+   |
+LL |     let _ = B::foo();
+   |                ^^^ function or associated item not found in `B`
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0599`.