Reduce use of elements/resolution_types in enqueuer.

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index 91167693fd689b811a4c81540cdf30baba1d9169..1d0587cbc48ac6520004351c3c16b8c9268e308a 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -944,7 +944,7 @@ abstract class Compiler implements LibraryLoaderListener {
     void checkLive(member) {
       if (member.isMalformed) return;
       if (member.isFunction) {
-        if (!enqueuer.resolution.hasBeenProcessed(member)) {
+        if (!resolutionWorldBuilder.isMemberUsed(member)) {
           reporter.reportHintMessage(
               member, MessageKind.UNUSED_METHOD, {'name': member.name});
         }