Support optional package name arguments to --show-package-warnings

pkg/compiler/lib/src/parser/partial_elements.dart

Index: pkg/compiler/lib/src/parser/partial_elements.dart
diff --git a/pkg/compiler/lib/src/parser/partial_elements.dart b/pkg/compiler/lib/src/parser/partial_elements.dart
index e26d83805b8607588e2780e935a9e4270b6bb9b9..d72c6b739766844947c00e838b1337753743555e 100644
--- a/pkg/compiler/lib/src/parser/partial_elements.dart
+++ b/pkg/compiler/lib/src/parser/partial_elements.dart
@@ -297,7 +297,9 @@ class PartialFieldList extends VariableList with PartialElement {
     // TODO(johnniwinther): Compute this in the resolver.
     VariableDefinitions node = parseNode(element, resolution.parsing);
     if (node.type != null) {
-      type = resolution.resolveTypeAnnotation(element, node.type);
+      type = resolution.reporter.withCurrentElement(element, () {
+        return resolution.resolveTypeAnnotation(element, node.type);
+      });
     } else {
       type = const DynamicType();
     }