Add unused_attributes to unused lint group.

Author: Lee Jeffery

src/librustc_lint/lib.rs

@@ -146,7 +146,7 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
     add_lint_group!(sess, "unused",
                     UNUSED_IMPORTS, UNUSED_VARIABLES, UNUSED_ASSIGNMENTS, DEAD_CODE,
                     UNUSED_MUT, UNREACHABLE_CODE, UNUSED_MUST_USE,
-                    UNUSED_UNSAFE, PATH_STATEMENTS);
+                    UNUSED_UNSAFE, PATH_STATEMENTS, UNUSED_ATTRIBUTES);
 
     // We have one lint pass defined specially
     store.register_late_pass(sess, false, box lint::GatherNodeLevels);

src/librustc_lint/unused.rs

@@ -235,7 +235,7 @@ impl LateLintPass for PathStatements {
 }
 
 declare_lint! {
-    UNUSED_ATTRIBUTES,
+    pub UNUSED_ATTRIBUTES,
     Warn,
     "detects attributes that were not used by the compiler"
 }