Add DCHECK that the script context table do not contain native scripts.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 967b07161f9ead03c71ba9974486935515dbe6fe..506b638ddea58dbe9d424a76c185e3c026a37912 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -3225,7 +3225,6 @@ Genesis::Genesis(Isolate* isolate,
       native_context()->set_natives_utils_object(
           isolate->heap()->undefined_value());
     }
-
     // The serializer cannot serialize typed arrays. Reset those typed arrays
     // for each new context.
     InitializeBuiltinTypedArrays();
@@ -3235,6 +3234,10 @@ Genesis::Genesis(Isolate* isolate,
     if (!InstallDebuggerNatives()) return;
   }
 
+  // Check that the script context table is empty except for the 'this' binding.
+  // We do not need script contexts for native scripts.
+  DCHECK_EQ(1, native_context()->script_context_table()->used());
+
   result_ = native_context();
 }