[builtins] Migrate StringFromCodePoint to C++.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 4e3c62cfbf8b8513385f922ed0263318248a7b1d..71b306c267221b75efb22907b4786ef565c322a8 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1372,6 +1372,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     SimpleInstallFunction(string_fun, "fromCharCode",
                           Builtins::kStringFromCharCode, 1, true);
 
+    // Install the String.fromCodePoint function.
+    SimpleInstallFunction(string_fun, "fromCodePoint",
+                          Builtins::kStringFromCodePoint, 1, false);
+
     // Create the %StringPrototype%
     Handle<JSValue> prototype =
         Handle<JSValue>::cast(factory->NewJSObject(string_fun, TENURED));