Refactor and clean up AccessSemantics

pkg/compiler/lib/src/resolution/send_resolver.dart

Index: pkg/compiler/lib/src/resolution/send_resolver.dart
diff --git a/pkg/compiler/lib/src/resolution/send_resolver.dart b/pkg/compiler/lib/src/resolution/send_resolver.dart
index d3f4e61a0de559b90d27e64d3d9d8df4771f6b1b..e23def359d5c2c93c8c3438af76d69ff2a54a68c 100644
--- a/pkg/compiler/lib/src/resolution/send_resolver.dart
+++ b/pkg/compiler/lib/src/resolution/send_resolver.dart
@@ -504,15 +504,15 @@ abstract class SendResolverMixin {
       // Conditional sends (e?.x) are treated as dynamic property reads because
       // they are equivalent to do ((a) => a == null ? null : a.x)(e). If `e` is
       // a type `A`, this is equivalent to write `(A).x`.
-      return new DynamicAccess.ifNotNullProperty(node.receiver);
+      return const DynamicAccess.ifNotNullProperty();
     } else if (node.isOperator) {
-      return new DynamicAccess.dynamicProperty(node.receiver);
+      return const DynamicAccess.dynamicProperty();
     } else if (Elements.isClosureSend(node, element)) {
       if (element == null) {
         if (node.selector.isThis()) {
-          return new AccessSemantics.thisAccess();
+          return new DynamicAccess.thisAccess();
         } else {
-          return new AccessSemantics.expression();
+          return new DynamicAccess.expression();
         }
       } else if (Elements.isErroneous(element)) {
         return new StaticAccess.unresolved(element);
@@ -526,9 +526,9 @@ abstract class SendResolverMixin {
       if (isDynamicAccess(element) &&
            (!isCompound || isDynamicAccess(getter))) {
         if (node.receiver == null || node.receiver.isThis()) {
-          return new AccessSemantics.thisProperty();
+          return const DynamicAccess.thisProperty();
         } else {
-          return new DynamicAccess.dynamicProperty(node.receiver);
+          return const DynamicAccess.dynamicProperty();
         }
       } else if (element != null && element.impliesType) {
         // TODO(johnniwinther): Provide an [ErroneousElement].