Decouple WorkItem from Compiler

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

Index: pkg/compiler/lib/src/universe/world_builder.dart
diff --git a/pkg/compiler/lib/src/universe/world_builder.dart b/pkg/compiler/lib/src/universe/world_builder.dart
index afcd031fa03d425c43a0238d7e4f53bd0a984827..49deb8eb047f2cc0efa0c8617f16fbed04a937b0 100644
--- a/pkg/compiler/lib/src/universe/world_builder.dart
+++ b/pkg/compiler/lib/src/universe/world_builder.dart
@@ -636,6 +636,7 @@ class ResolutionWorldBuilderImpl implements ResolutionWorldBuilder {
         methodsNeedingSuperGetter.add(element);
         break;
       case StaticUseKind.GENERAL:
+      case StaticUseKind.DIRECT_USE:
       case StaticUseKind.STATIC_TEAR_OFF:
       case StaticUseKind.FIELD_GET:
       case StaticUseKind.CONSTRUCTOR_INVOKE:
@@ -911,6 +912,7 @@ class CodegenWorldBuilderImpl implements CodegenWorldBuilder {
       case StaticUseKind.SUPER_FIELD_SET:
       case StaticUseKind.FIELD_SET:
       case StaticUseKind.GENERAL:
+      case StaticUseKind.DIRECT_USE:
       case StaticUseKind.CLOSURE:
       case StaticUseKind.FIELD_GET:
       case StaticUseKind.CONSTRUCTOR_INVOKE: