Revert "Snapshot i18n Javascript code" and "Fix mjsunit/debug-script after r16298".

src/mksnapshot.cc

Index: src/mksnapshot.cc
diff --git a/src/mksnapshot.cc b/src/mksnapshot.cc
index a4b5ae1ed8955b6a091c64f75de9611fc845ff33..c1edcb1b3a149d462dd9e071e0f9fad043c913bd 100644
--- a/src/mksnapshot.cc
+++ b/src/mksnapshot.cc
@@ -314,6 +314,9 @@ int main(int argc, char** argv) {
   // By default, log code create information in the snapshot.
   i::FLAG_log_code = true;
 
+  // Disable the i18n extension, as it doesn't support being snapshotted yet.
+  i::FLAG_enable_i18n = 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);