Revert of [es2015] Precompute the descriptive string for symbols.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 5d4946f520c2de88a6e5fada0c66ed6ff87b91f5..faa04848cff43c13c49ff5837ecb6718deac3822 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -3270,8 +3270,9 @@
   int entry = dictionary->FindEntry(key);
   Handle<Symbol> symbol;
   if (entry == NameDictionary::kNotFound) {
-    symbol = private_symbol ? factory()->NewPrivateSymbol(key).ToHandleChecked()
-                            : factory()->NewSymbol(key).ToHandleChecked();
+    symbol =
+        private_symbol ? factory()->NewPrivateSymbol() : factory()->NewSymbol();
+    symbol->set_name(*key);
     dictionary = NameDictionary::Add(dictionary, key, symbol,
                                      PropertyDetails::Empty(), &entry);
     switch (dictionary_index) {