Improve rendering of crate features via doc(cfg)

Author: Nemo157

src/librustdoc/clean/cfg.rs

@@ -413,6 +413,13 @@ impl<'a> fmt::Display for Html<'a> {
                             return write!(fmt, "target feature <code>{}</code>", feat);
                         }
                     }
+                    (sym::feature, Some(feat)) => {
+                        if self.1 {
+                            return write!(fmt, "<code>{}</code>", feat);
+                        } else {
+                            return write!(fmt, "crate feature <code>{}</code>", feat);
+                        }
+                    }
                     _ => "",
                 };
                 if !human_readable.is_empty() {

src/test/rustdoc/duplicate-cfg.rs

@@ -4,37 +4,37 @@
 #![feature(doc_cfg)]
 
 // @has 'foo/struct.Foo.html'
-// @has '-' '//*[@class="stab portability"]' 'This is supported on feature="sync" only.'
+// @has '-' '//*[@class="stab portability"]' 'This is supported on crate feature sync only.'
 #[doc(cfg(feature = "sync"))]
 #[doc(cfg(feature = "sync"))]
 pub struct Foo;
 
 // @has 'foo/bar/struct.Bar.html'
-// @has '-' '//*[@class="stab portability"]' 'This is supported on feature="sync" only.'
+// @has '-' '//*[@class="stab portability"]' 'This is supported on crate feature sync only.'
 #[doc(cfg(feature = "sync"))]
 pub mod bar {
     #[doc(cfg(feature = "sync"))]
     pub struct Bar;
 }
 
 // @has 'foo/baz/struct.Baz.html'
-// @has '-' '//*[@class="stab portability"]' 'This is supported on feature="sync" and feature="send" only.'
+// @has '-' '//*[@class="stab portability"]' 'This is supported on crate feature sync and crate feature send only.'
 #[doc(cfg(all(feature = "sync", feature = "send")))]
 pub mod baz {
     #[doc(cfg(feature = "sync"))]
     pub struct Baz;
 }
 
 // @has 'foo/qux/struct.Qux.html'
-// @has '-' '//*[@class="stab portability"]' 'This is supported on feature="sync" and feature="send" only.'
+// @has '-' '//*[@class="stab portability"]' 'This is supported on crate feature sync and crate feature send only.'
 #[doc(cfg(feature = "sync"))]
 pub mod qux {
     #[doc(cfg(all(feature = "sync", feature = "send")))]
     pub struct Qux;
 }
 
 // @has 'foo/quux/struct.Quux.html'
-// @has '-' '//*[@class="stab portability"]' 'This is supported on feature="sync" and feature="send" and foo and bar only.'
+// @has '-' '//*[@class="stab portability"]' 'This is supported on crate feature sync and crate feature send and foo and bar only.'
 #[doc(cfg(all(feature = "sync", feature = "send", foo)))]
 pub mod quux {
     #[doc(cfg(all(feature = "send", feature = "sync", bar)))]