[builtins] Remove SymbolConstructor_ConstructStub builtin

This brings us closer to our goal of deprecating the `construct_stub`
field in `SharedFunctionInfo`.

Bug: v8:7503
Change-Id: Id7bee0d61830f7bcf2cad4f6e50ff9f24b58a51b
Reviewed-on: https://chromium-review.googlesource.com/939790Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51633}

src/bootstrapper.cc

@@ -2119,7 +2119,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
         factory->the_hole_value(), Builtins::kSymbolConstructor);
     symbol_fun->shared()->set_builtin_function_id(kSymbolConstructor);
     symbol_fun->shared()->SetConstructStub(
-        *BUILTIN_CODE(isolate, SymbolConstructor_ConstructStub));
+        *BUILTIN_CODE(isolate, JSBuiltinsConstructStub));
     symbol_fun->shared()->set_length(0);
     symbol_fun->shared()->DontAdaptArguments();
     native_context()->set_symbol_function(*symbol_fun);

src/builtins/builtins-definitions.h

@@ -1061,8 +1061,8 @@ namespace internal {
   TFJ(StringIteratorPrototypeNext, 0)                                          \
                                                                                \
   /* Symbol */                                                                 \
+  /* ES #sec-symbol-constructor */                                             \
   CPP(SymbolConstructor)                                                       \
-  CPP(SymbolConstructor_ConstructStub)                                         \
   /* ES6 #sec-symbol.for */                                                    \
   CPP(SymbolFor)                                                               \
   /* ES6 #sec-symbol.keyfor */                                                 \

src/builtins/builtins-symbol.cc

@@ -11,27 +11,25 @@ namespace v8 {
 namespace internal {
 
 // -----------------------------------------------------------------------------
-// ES6 section 19.4 Symbol Objects
+// ES #sec-symbol-objects
 
-// ES6 section 19.4.1.1 Symbol ( [ description ] ) for the [[Call]] case.
+// ES #sec-symbol-constructor
 BUILTIN(SymbolConstructor) {
   HandleScope scope(isolate);
-  Handle<Symbol> result = isolate->factory()->NewSymbol();
-  Handle<Object> description = args.atOrUndefined(isolate, 1);
-  if (!description->IsUndefined(isolate)) {
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, description,
-                                       Object::ToString(isolate, description));
-    result->set_name(*description);
+  if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
+    Handle<Symbol> result = isolate->factory()->NewSymbol();
+    Handle<Object> description = args.atOrUndefined(isolate, 1);
+    if (!description->IsUndefined(isolate)) {
+      ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+          isolate, description, Object::ToString(isolate, description));
+      result->set_name(*description);
+    }
+    return *result;
+  } else {  // [[Construct]]
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewTypeError(MessageTemplate::kNotConstructor,
+                              isolate->factory()->Symbol_string()));
   }
-  return *result;
-}
-
-// ES6 section 19.4.1.1 Symbol ( [ description ] ) for the [[Construct]] case.
-BUILTIN(SymbolConstructor_ConstructStub) {
-  HandleScope scope(isolate);
-  THROW_NEW_ERROR_RETURN_FAILURE(
-      isolate, NewTypeError(MessageTemplate::kNotConstructor,
-                            isolate->factory()->Symbol_string()));
 }
 
 // ES6 section 19.4.2.1 Symbol.for.