Put back the asserts in RememberedSetHelper, but correct this time.

src/ia32/macro-assembler-ia32.cc

 // Copyright 2011 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 61 matching lines @@
   int mask = (1 << MemoryChunk::IN_FROM_SPACE)
            | (1 << MemoryChunk::IN_TO_SPACE);
   // If non-zero, the page belongs to new-space.
   test_b(Operand(scratch, MemoryChunk::kFlagsOffset),
          static_cast<uint8_t>(mask));
   j(cc, condition_met, condition_met_distance);
 }
 
 
 void MacroAssembler::RememberedSetHelper(
+    Register object,  // Only used for debug checks.
     Register addr,
     Register scratch,
     SaveFPRegsMode save_fp,
     MacroAssembler::RememberedSetFinalAction and_then) {
   Label done;
+  if (FLAG_debug_code) {
+    Label ok;
+    JumpIfNotInNewSpace(object, scratch, &ok, Label::kNear);
+    int3();
+    bind(&ok);
+  }
   // Load store buffer top.
   ExternalReference store_buffer =
       ExternalReference::store_buffer_top(isolate());
   mov(scratch, Operand::StaticVariable(store_buffer));
   // Store pointer to buffer.
   mov(Operand(scratch, 0), addr);
   // Increment buffer top.
   add(Operand(scratch), Immediate(kPointerSize));
   // Write back new top of buffer.
   mov(Operand::StaticVariable(store_buffer), scratch);
@@ skipping 2511 matching lines @@
     cmp(length, Operand(bitmap_scratch, MemoryChunk::kSizeOffset));
     Check(less_equal, "Live Bytes Count overflow chunk size");
   }
 
   bind(&done);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32