Return Object* instead of MaybeObject* from runtime calls.

src/arguments.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 281 matching lines @@
 double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
 
 
 #ifdef DEBUG
 #define CLOBBER_DOUBLE_REGISTERS() ClobberDoubleRegisters(1, 2, 3, 4);
 #else
 #define CLOBBER_DOUBLE_REGISTERS()
 #endif
 
 
-#define DECLARE_RUNTIME_FUNCTION(Type, Name)    \
-Type Name(int args_length, Object** args_object, Isolate* isolate)
+#define DECLARE_RUNTIME_FUNCTION(Name)    \
+Object* Name(int args_length, Object** args_object, Isolate* isolate)
 
-#define RUNTIME_FUNCTION(Type, Name)                                  \
+#define RUNTIME_FUNCTION_RETURNS_TYPE(Type, Name)                     \
 static Type __RT_impl_##Name(Arguments args, Isolate* isolate);       \
 Type Name(int args_length, Object** args_object, Isolate* isolate) {  \
   CLOBBER_DOUBLE_REGISTERS();                                         \
   Arguments args(args_length, args_object);                           \
   return __RT_impl_##Name(args, isolate);                             \
 }                                                                     \
 static Type __RT_impl_##Name(Arguments args, Isolate* isolate)
 
+
+#define RUNTIME_FUNCTION(Name) RUNTIME_FUNCTION_RETURNS_TYPE(Object*, Name)
+#define RUNTIME_FUNCTION_RETURN_PAIR(Name) \
+    RUNTIME_FUNCTION_RETURNS_TYPE(ObjectPair, Name)
+
 #define RUNTIME_ARGUMENTS(isolate, args) \
   args.length(), args.arguments(), isolate
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARGUMENTS_H_