Support stepin for combination of apply and bound function

src/debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1775 matching lines @@
     } else if (!function->IsBuiltin()) {
       // Don't allow step into functions in the native context.
       if (function->shared()->code() ==
           isolate->builtins()->builtin(Builtins::kFunctionApply) ||
           function->shared()->code() ==
           isolate->builtins()->builtin(Builtins::kFunctionCall)) {
         // Handle function.apply and function.call separately to flood the
         // function to be called and not the code for Builtins::FunctionApply or
         // Builtins::FunctionCall. The receiver of call/apply is the target
         // function.
-        if (!holder.is_null() && holder->IsJSFunction() &&
-            !JSFunction::cast(*holder)->IsBuiltin()) {
+        if (!holder.is_null() && holder->IsJSFunction()) {
           Handle<JSFunction> js_function = Handle<JSFunction>::cast(holder);
-          Debug::FloodWithOneShot(js_function);
+          if (!js_function->IsBuiltin()) {
+            Debug::FloodWithOneShot(js_function);
+          } else if (js_function->shared()->bound()) {
+            // Handle Function.prototype.bind
+            Debug::FloodBoundFunctionWithOneShot(js_function);
+          }
         }
       } else {
         Debug::FloodWithOneShot(function);
       }
     }
   }
 }
 
 
 void Debug::ClearStepping() {
@@ skipping 2034 matching lines @@
     {
       Locker locker(reinterpret_cast<v8::Isolate*>(isolate_));
       isolate_->debugger()->CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal