Sort the output (for now just the classes and instance members).

lib/compiler/implementation/scanner/byte_strings.dart

Index: lib/compiler/implementation/scanner/byte_strings.dart
diff --git a/lib/compiler/implementation/scanner/byte_strings.dart b/lib/compiler/implementation/scanner/byte_strings.dart
index c9b18d0c83217775d85059563f49435ad4c57b26..aa92be3070d07750fb7a3401284b8a3771847754 100644
--- a/lib/compiler/implementation/scanner/byte_strings.dart
+++ b/lib/compiler/implementation/scanner/byte_strings.dart
@@ -42,6 +42,8 @@ class ByteString implements SourceString {
     return code;
   }
 
+  int compareTo(SourceString other) => sourceStringCompare(this, other);
+
   printOn(StringBuffer sb) {
     sb.add(slowToString());
   }