Tests for `void`.

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

Index: pkg/compiler/lib/src/resolution/resolution.dart
diff --git a/pkg/compiler/lib/src/resolution/resolution.dart b/pkg/compiler/lib/src/resolution/resolution.dart
index 5706455830bcd7eb529e160555c97cf6c44f21ee..8d53c06e4a34f17cd7afa2bbd2e966c0efae26ed 100644
--- a/pkg/compiler/lib/src/resolution/resolution.dart
+++ b/pkg/compiler/lib/src/resolution/resolution.dart
@@ -442,15 +442,6 @@ class ResolverTask extends CompilerTask {
 
   ResolutionDartType resolveTypeAnnotation(
       Element element, TypeAnnotation annotation) {
-    ResolutionDartType type = _resolveReturnType(element, annotation);
-    if (type.isVoid) {
-      reporter.reportErrorMessage(annotation, MessageKind.VOID_NOT_ALLOWED);
-    }
-    return type;
-  }
-
-  ResolutionDartType _resolveReturnType(
-      Element element, TypeAnnotation annotation) {
     if (annotation == null) return const ResolutionDynamicType();
     ResolutionDartType result =
         visitorFor(element).resolveTypeAnnotation(annotation);