Parse script tags with Fasta.

pkg/front_end/lib/src/fasta/source/diet_listener.dart

Index: pkg/front_end/lib/src/fasta/source/diet_listener.dart
diff --git a/pkg/front_end/lib/src/fasta/source/diet_listener.dart b/pkg/front_end/lib/src/fasta/source/diet_listener.dart
index bbbb2085806d6e47b431ead8025435b6eb42142e..c1ea10db2b4837da06eeeb861a0e29e6ad4c244e 100644
--- a/pkg/front_end/lib/src/fasta/source/diet_listener.dart
+++ b/pkg/front_end/lib/src/fasta/source/diet_listener.dart
@@ -262,6 +262,11 @@ class DietListener extends StackListener {
   }
 
   @override
+  void handleScript(Token token) {
+    debugEvent("Script");
+  }
+
+  @override
   void handleStringJuxtaposition(int literalCount) {
     debugEvent("StringJuxtaposition");
   }