[stubs] Port String.prototype.substr to TurboFan

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/base/ieee754.h"
 #include "src/code-stubs.h"
@@ skipping 1386 matching lines @@
     SimpleInstallFunction(prototype, "charAt", Builtins::kStringPrototypeCharAt,
                           1, true);
     SimpleInstallFunction(prototype, "charCodeAt",
                           Builtins::kStringPrototypeCharCodeAt, 1, true);
     SimpleInstallFunction(prototype, "lastIndexOf",
                           Builtins::kStringPrototypeLastIndexOf, 1, false);
     SimpleInstallFunction(prototype, "localeCompare",
                           Builtins::kStringPrototypeLocaleCompare, 1, true);
     SimpleInstallFunction(prototype, "normalize",
                           Builtins::kStringPrototypeNormalize, 0, false);
+    SimpleInstallFunction(prototype, "substr", Builtins::kStringPrototypeSubstr,
+                          2, true);
     SimpleInstallFunction(prototype, "substring",
                           Builtins::kStringPrototypeSubstring, 2, true);
     SimpleInstallFunction(prototype, "toString",
                           Builtins::kStringPrototypeToString, 0, true);
     SimpleInstallFunction(prototype, "trim", Builtins::kStringPrototypeTrim, 0,
                           false);
     SimpleInstallFunction(prototype, "trimLeft",
                           Builtins::kStringPrototypeTrimLeft, 0, false);
     SimpleInstallFunction(prototype, "trimRight",
                           Builtins::kStringPrototypeTrimRight, 0, false);
@@ skipping 2768 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8