Add an optional bound to type parameter references

pkg/kernel/lib/binary/ast_from_binary.dart

Index: pkg/kernel/lib/binary/ast_from_binary.dart
diff --git a/pkg/kernel/lib/binary/ast_from_binary.dart b/pkg/kernel/lib/binary/ast_from_binary.dart
index 86503ffa388ef04947663d934bce031e921808d2..e5af2a3c15128688b872bfda65d12f65ce669224 100644
--- a/pkg/kernel/lib/binary/ast_from_binary.dart
+++ b/pkg/kernel/lib/binary/ast_from_binary.dart
@@ -1084,7 +1084,8 @@ class BinaryBuilder {
         return new FunctionType(positional, returnType);
       case Tag.TypeParameterType:
         int index = readUInt();
-        return new TypeParameterType(typeParameterStack[index]);
+        var bound = readDartTypeOption();
+        return new TypeParameterType(typeParameterStack[index], bound);
       default:
         throw fail('Invalid dart type tag: $tag');
     }