Introduce a kill-switch for shipping features.

src/mksnapshot.cc

Index: src/mksnapshot.cc
diff --git a/src/mksnapshot.cc b/src/mksnapshot.cc
index 3264f3743f7f166fbbe239c1bd572c8bbc98d376..544e7393eae59da5d79f81cfcf760e30248ae9ef 100644
--- a/src/mksnapshot.cc
+++ b/src/mksnapshot.cc
@@ -262,6 +262,10 @@ int main(int argc, char** argv) {
   // By default, log code create information in the snapshot.
   i::FLAG_log_code = true;
 
+  // Omit from the snapshot natives for features that can be turned off
+  // at runtime.
+  i::FLAG_harmony_shipping = false;
+
   // Print the usage if an error occurs when parsing the command line
   // flags or if the help flag is set.
   int result = i::FlagList::SetFlagsFromCommandLine(&argc, argv, true);