map_dependencies is doing a deep clone, so lets make it cheaper

Author: Eh2406

src/cargo/core/summary.rs

@@ -26,7 +26,7 @@ pub struct Summary {
 struct Inner {
     package_id: PackageId,
     dependencies: Vec<Dependency>,
-    features: FeatureMap,
+    features: Rc<FeatureMap>,
     checksum: Option<String>,
     links: Option<InternedString>,
     namespaced_features: bool,
@@ -64,7 +64,7 @@ impl Summary {
             inner: Rc::new(Inner {
                 package_id: pkg_id,
                 dependencies,
-                features: feature_map,
+                features: Rc::new(feature_map),
                 checksum: None,
                 links: links.map(|l| l.into()),
                 namespaced_features,