Provide baseline for experimental GC implementation.

src/ia32/macro-assembler-ia32.h

Index: src/ia32/macro-assembler-ia32.h
diff --git a/src/ia32/macro-assembler-ia32.h b/src/ia32/macro-assembler-ia32.h
index 8407802104dee42e20b9f284caa1856f1fa302d9..44a9d49923c0d31b63572847355abbf2336b0e8f 100644
--- a/src/ia32/macro-assembler-ia32.h
+++ b/src/ia32/macro-assembler-ia32.h
@@ -61,6 +61,7 @@ class MacroAssembler: public Assembler {
   // ---------------------------------------------------------------------------
   // GC Support
 
+#ifdef ENABLE_CARDMARKING_WRITE_BARRIER
   // For page containing |object| mark region covering |addr| dirty.
   // RecordWriteHelper only works if the object is not in new
   // space.
@@ -95,6 +96,7 @@ class MacroAssembler: public Assembler {
   void RecordWrite(Register object,
                    Register address,
                    Register value);
+#endif
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // ---------------------------------------------------------------------------