[builtins] Migrate the leftover Boolean setup to C++.

src/bootstrapper.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 1226 matching lines @@
     Handle<JSFunction> boolean_fun =
         InstallFunction(global, "Boolean", JS_VALUE_TYPE, JSValue::kSize,
                         isolate->initial_object_prototype(),
                         Builtins::kBooleanConstructor);
     boolean_fun->shared()->DontAdaptArguments();
     boolean_fun->shared()->set_construct_stub(
         *isolate->builtins()->BooleanConstructor_ConstructStub());
     boolean_fun->shared()->set_length(1);
     InstallWithIntrinsicDefaultProto(isolate, boolean_fun,
                                      Context::BOOLEAN_FUNCTION_INDEX);
+
+    // Create the %BooleanPrototype%
+    Handle<JSValue> prototype =
+        Handle<JSValue>::cast(factory->NewJSObject(boolean_fun, TENURED));
+    prototype->set_value(isolate->heap()->false_value());
+    Accessors::FunctionSetPrototype(boolean_fun, prototype).Assert();
+
+    // Install the "constructor" property on the {prototype}.
+    JSObject::AddProperty(prototype, factory->constructor_string(), boolean_fun,
+                          DONT_ENUM);
+
+    // Install the Boolean.prototype methods.
+    SimpleInstallFunction(prototype, "toString",
+                          Builtins::kBooleanPrototypeToString, 0, false);
+    SimpleInstallFunction(prototype, "valueOf",
+                          Builtins::kBooleanPrototypeValueOf, 0, false);
   }
 
   {  // --- S t r i n g ---
     Handle<JSFunction> string_fun = InstallFunction(
         global, "String", JS_VALUE_TYPE, JSValue::kSize,
         isolate->initial_object_prototype(), Builtins::kStringConstructor);
     string_fun->shared()->set_construct_stub(
         *isolate->builtins()->StringConstructor_ConstructStub());
     string_fun->shared()->DontAdaptArguments();
     string_fun->shared()->set_length(1);
@@ skipping 2398 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8