Fix crash when reporting error involving constructor.

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

Index: pkg/front_end/lib/src/fasta/kernel/body_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 971aab6145d9b469fdd6c68f800a9839c016c94f..d52d0ed4f2e09ae891afc4ad7ceb3eed030081ad 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -2703,8 +2703,10 @@ String getNodeName(Object node) {
     return node.name;
   } else if (node is PrefixBuilder) {
     return node.name;
-  } else if (node is ThisPropertyAccessor) {
-    return node.name.name;
+  } else if (node is ThisAccessor) {
+    return node.isSuper ? "super" : "this";
+  } else if (node is BuilderAccessor) {
+    return node.plainNameForRead;
   } else {
     return internalError("Unhandled: ${node.runtimeType}");
   }