Move dart_types to elements/resolution_types

pkg/compiler/lib/src/universe/feature.dart

 // TODO(sigmund): rename universe => world
 /// Describes individual features that may be seen in a program. Most features
 /// can be described only by name using the [Feature] enum, some features are
 /// expressed including details on how they are used. For example, whether a
 /// list literal was constant or empty.
 ///
 /// The use of these features is typically discovered in an early phase of the
 /// compilation pipeline, for example during resolution.
 library compiler.universe.feature;
 
-import '../dart_types.dart' show InterfaceType;
+import '../elements/resolution_types.dart' show InterfaceType;
 
 /// A language feature that may be seen in the program.
 // TODO(johnniwinther): Should mirror usage be part of this?
 enum Feature {
   /// Invocation of a generative construction on an abstract class.
   ABSTRACT_CLASS_INSTANTIATION,
 
   /// An assert statement with no message.
   ASSERT,
 
@@ skipping 110 matching lines @@
     if (other is! ListLiteralUse) return false;
     return type == other.type &&
         isConstant == other.isConstant &&
         isEmpty == other.isEmpty;
   }
 
   String toString() {
     return 'ListLiteralUse($type,isConstant:$isConstant,isEmpty:$isEmpty)';
   }
 }