Use signature inheritance when method types are unchanged

test/codegen/expect/misc.js

Index: test/codegen/expect/misc.js
diff --git a/test/codegen/expect/misc.js b/test/codegen/expect/misc.js
index 52cbd985010e04603040e08696a7ca7a06eb6fdc..02de8f38dcd6d1004cca58ce22a4048cb2bd56a4 100644
--- a/test/codegen/expect/misc.js
+++ b/test/codegen/expect/misc.js
@@ -6,7 +6,6 @@ var core = dart.import(core);
     _Uninitialized() {
     }
   }
-  dart.setSignature(_Uninitialized, {});
   let UNINITIALIZED = dart.const(new _Uninitialized());
   let Generic$ = dart.generic(function(T) {
     class Generic extends core.Object {
@@ -14,7 +13,6 @@ var core = dart.import(core);
         return Generic$();
       }
     }
-    dart.setSignature(Generic, {});
     return Generic;
   });
   let Generic = Generic$();