toString() on generator functions prints with function*

src/runtime.h

 // 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 213 matching lines @@
 #define RUNTIME_FUNCTION_LIST_ALWAYS_2(F) \
   /* Reflection */ \
   F(FunctionSetInstanceClassName, 2, 1) \
   F(FunctionSetLength, 2, 1) \
   F(FunctionSetPrototype, 2, 1) \
   F(FunctionSetReadOnlyPrototype, 1, 1) \
   F(FunctionGetName, 1, 1) \
   F(FunctionSetName, 2, 1) \
   F(FunctionNameShouldPrintAsAnonymous, 1, 1) \
   F(FunctionMarkNameShouldPrintAsAnonymous, 1, 1) \
+  F(FunctionIsGenerator, 1, 1) \
   F(FunctionBindArguments, 4, 1) \
   F(BoundFunctionGetBindings, 1, 1) \
   F(FunctionRemovePrototype, 1, 1) \
   F(FunctionGetSourceCode, 1, 1) \
   F(FunctionGetScript, 1, 1) \
   F(FunctionGetScriptSourcePosition, 1, 1) \
   F(FunctionGetPositionForOffset, 2, 1) \
   F(FunctionIsAPIFunction, 1, 1) \
   F(FunctionIsBuiltin, 1, 1) \
   F(GetScript, 1, 1) \
@@ skipping 529 matching lines @@
 //---------------------------------------------------------------------------
 // Constants used by interface to runtime functions.
 
 class DeclareGlobalsEvalFlag:     public BitField<bool,         0, 1> {};
 class DeclareGlobalsNativeFlag:   public BitField<bool,         1, 1> {};
 class DeclareGlobalsLanguageMode: public BitField<LanguageMode, 2, 2> {};
 
 } }  // namespace v8::internal
 
 #endif  // V8_RUNTIME_H_