Add @files checks in rustdoc tests

Author: GuillaumeGomez

tests/rustdoc/files-creation-hidden.rs

@@ -1,5 +1,6 @@
 #![crate_name="foo"]
 
+// @files foo '["index.html", "all.html", "sidebar-items.js"]'
 // @!has "foo/struct.Foo.html"
 #[doc(hidden)]
 pub struct Foo;

tests/rustdoc/files-creation-private.rs

@@ -1,5 +1,9 @@
 #![crate_name="foo"]
 
+// @files "foo" \
+// '["index.html", "all.html", "sidebar-items.js", "foo", "bar", "private", "struct.Bar.html"]'
+// @files "foo/bar" '["index.html", "sidebar-items.js"]'
+
 // @!has "foo/priv/index.html"
 // @!has "foo/priv/struct.Foo.html"
 mod private {

tests/rustdoc/issue-111064-reexport-trait-from-hidden-2.rs

@@ -2,6 +2,12 @@
 #![no_core]
 #![crate_name = "foo"]
 
+// @files "foo" "['sidebar-items.js', 'all.html', 'hidden', 'index.html', 'struct.Bar.html', \
+//        'visible']"
+// @files "foo/hidden" "['inner']"
+// @files "foo/hidden/inner" "['trait.Foo.html']"
+// @files "foo/visible" "['index.html', 'sidebar-items.js', 'trait.Foo.html']"
+
 // @!has 'foo/hidden/index.html'
 // @!has 'foo/hidden/inner/index.html'
 // FIXME: Should be `@!has`: https://github.com/rust-lang/rust/issues/111249

tests/rustdoc/issue-111249-file-creation.rs

@@ -2,6 +2,12 @@
 #![feature(no_core)]
 #![no_core]
 
+// @files "foo" "['all.html', 'visible', 'index.html', 'sidebar-items.js', 'hidden', \
+//        'struct.Bar.html']"
+// @files "foo/visible" "['trait.Foo.html', 'index.html', 'sidebar-items.js']"
+// @files "foo/hidden" "['inner']"
+// @files "foo/hidden/inner" "['trait.Foo.html']"
+
 // The following five should not fail!
 // @!has 'foo/hidden/index.html'
 // @!has 'foo/hidden/inner/index.html'