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

src/arm/macro-assembler-arm.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 505 matching lines @@
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
   if (emit_debug_code()) {
     mov(address, Operand(BitCast<int32_t>(kZapValue + 12)));
     mov(value, Operand(BitCast<int32_t>(kZapValue + 16)));
   }
 }
 
 
-void MacroAssembler::RememberedSetHelper(Register address,
+void MacroAssembler::RememberedSetHelper(Register object,  // For debug tests.
+                                         Register address,
                                          Register scratch,
                                          SaveFPRegsMode fp_mode,
                                          RememberedSetFinalAction and_then) {
   Label done;
+  if (FLAG_debug_code) {
+    Label ok;
+    JumpIfNotInNewSpace(object, scratch, &ok);
+    stop("Remembered set pointer is in new space");
+    bind(&ok);
+  }
   // Load store buffer top.
   ExternalReference store_buffer =
       ExternalReference::store_buffer_top(isolate());
   mov(ip, Operand(store_buffer));
   ldr(scratch, MemOperand(ip));
   // Store pointer to buffer and increment buffer top.
   str(address, MemOperand(scratch, kPointerSize, PostIndex));
   // Write back new top of buffer.
   str(scratch, MemOperand(ip));
   // Call stub on end of buffer.
@@ skipping 3004 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM