[builtins] Migrate String.fromCharCode 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 1302 matching lines @@
         DONT_ENUM | DONT_DELETE | READ_ONLY);
     Handle<AccessorInfo> string_length(
         Accessors::StringLengthInfo(isolate, attribs));
 
     {  // Add length.
       AccessorConstantDescriptor d(factory->length_string(), string_length,
                                    attribs);
       string_map->AppendDescriptor(&d);
     }
 
+    // Install the String.fromCharCode function.
+    SimpleInstallFunction(string_fun, "fromCharCode",
+                          Builtins::kStringFromCharCode, 1, false);
+
     // Create the %StringPrototype%
     Handle<JSValue> prototype =
         Handle<JSValue>::cast(factory->NewJSObject(string_fun, TENURED));
     prototype->set_value(isolate->heap()->empty_string());
     Accessors::FunctionSetPrototype(string_fun, prototype).Assert();
 
     // Install the "constructor" property on the {prototype}.
     JSObject::AddProperty(prototype, factory->constructor_string(), string_fun,
                           DONT_ENUM);
 
@@ skipping 2439 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8