Don't add code dependencies eagerly for HCheckMaps.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index f324df4963fda147f57b8c749638d2a164e491dd..fe6f79463e08c74c922e1ea65086fe993f722384 100644
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -2399,7 +2399,7 @@ class LCheckInstanceType V8_FINAL : public LTemplateInstruction<0, 1, 1> {
 
 class LCheckMaps V8_FINAL : public LTemplateInstruction<0, 1, 0> {
  public:
-  explicit LCheckMaps(LOperand* value) {
+  explicit LCheckMaps(LOperand* value = NULL) {
     inputs_[0] = value;
   }