Eliminate extended mode, and other modes clean-up

src/variables.cc

Index: src/variables.cc
diff --git a/src/variables.cc b/src/variables.cc
index 488da42ce665ed7322ca7f53e27fc3ec9c109e58..6c4ea527ca76c256f325af66cef4e2caed4b04ee 100644
--- a/src/variables.cc
+++ b/src/variables.cc
@@ -40,9 +40,9 @@ namespace internal {
 const char* Variable::Mode2String(VariableMode mode) {
   switch (mode) {
     case VAR: return "VAR";
-    case CONST: return "CONST";
+    case CONST_LEGACY: return "CONST_LEGACY";
     case LET: return "LET";
-    case CONST_HARMONY: return "CONST_HARMONY";
+    case CONST: return "CONST";
     case MODULE: return "MODULE";
     case DYNAMIC: return "DYNAMIC";
     case DYNAMIC_GLOBAL: return "DYNAMIC_GLOBAL";