[builtins] Move StringIncludes to a builtin.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 45957f10b057779f6429baedad1babaa90419bec..8ae2d3cc8ffe7ed98ac611f9f808c1b8db85a980 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1437,6 +1437,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           1, true);
     SimpleInstallFunction(prototype, "charCodeAt",
                           Builtins::kStringPrototypeCharCodeAt, 1, true);
+    SimpleInstallFunction(prototype, "includes",
+                          Builtins::kStringPrototypeIncludes, 1, false);
     SimpleInstallFunction(prototype, "indexOf",
                           Builtins::kStringPrototypeIndexOf, 1, false);
     SimpleInstallFunction(prototype, "lastIndexOf",