[builtins] Support SameValue and SameValueZero via runtime functions.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 2136fd087dad75a7abb77491e837cb3d6103204a..be6daf4b8dd806b622beb9a62327250a25498ebd 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1103,6 +1103,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kObjectGetOwnPropertyNames, 1, false);
     SimpleInstallFunction(object_function, "getOwnPropertySymbols",
                           Builtins::kObjectGetOwnPropertySymbols, 1, false);
+    SimpleInstallFunction(object_function, "is", Builtins::kObjectIs, 2, true);
     Handle<JSFunction> object_is_extensible =
         SimpleInstallFunction(object_function, "isExtensible",
                               Builtins::kObjectIsExtensible, 1, false);