rustc: Remove the meta keyword

Issue #487

src/comp/middle/visit.rs

@@ -73,7 +73,6 @@ fn visit_crate_directive[E](&@crate_directive cd, &E e, &vt[E] v) {
             }
         }
         case (cdir_view_item(?vi)) { vt(v).visit_view_item(vi, e, v); }
-        case (cdir_meta(_, _)) { }
         case (cdir_syntax(_)) { }
         case (cdir_auth(_, _)) { }
     }

src/comp/middle/walk.rs

@@ -70,7 +70,6 @@ fn walk_crate_directive(&ast_visitor v, @ast::crate_directive cd) {
             }
         }
         case (ast::cdir_view_item(?vi)) { walk_view_item(v, vi); }
-        case (ast::cdir_meta(_, _)) { }
         case (ast::cdir_syntax(_)) { }
         case (ast::cdir_auth(_, _)) { }
     }