toString() on generator functions prints with function*

src/runtime.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 2171 matching lines @@
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionMarkNameShouldPrintAsAnonymous) {
   NoHandleAllocation ha(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_CHECKED(JSFunction, f, 0);
   f->shared()->set_name_should_print_as_anonymous(true);
   return isolate->heap()->undefined_value();
 }
 
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionIsGenerator) {
+  NoHandleAllocation ha(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSFunction, f, 0);
+  return isolate->heap()->ToBoolean(f->shared()->is_generator());
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionRemovePrototype) {
   NoHandleAllocation ha(isolate);
   ASSERT(args.length() == 1);
 
   CONVERT_ARG_CHECKED(JSFunction, f, 0);
   f->RemovePrototype();
 
   return isolate->heap()->undefined_value();
 }
 
@@ skipping 11175 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal