Remember to update the write barrier when storing into...

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
===================================================================
--- src/ia32/macro-assembler-ia32.cc	(revision 3760)
+++ src/ia32/macro-assembler-ia32.cc	(working copy)
@@ -215,6 +215,14 @@
   }
 
   bind(&done);
+
+  // Clobber all input registers when running with the debug-code flag
+  // turned on to provoke errors.
+  if (FLAG_debug_code) {
+    mov(object, Immediate(bit_cast<int32_t>(kZapValue)));
+    mov(value, Immediate(bit_cast<int32_t>(kZapValue)));
+    mov(scratch, Immediate(bit_cast<int32_t>(kZapValue)));
+  }
 }