Don't add code dependencies eagerly for HCheckMaps.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index b3a1c30f37fa200338789f9737d9b38401558d79..c49fa930f88f6620bfc0fe96939380a7bbd9a639 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -5013,14 +5013,20 @@ void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
     Register object_;
   };
 
-  if (instr->hydrogen()->CanOmitMapChecks()) return;
+  if (instr->hydrogen()->IsStabilityCheck()) {
+    const UniqueSet<Map>* maps = instr->hydrogen()->maps();
+    for (int i = 0; i < maps->size(); ++i) {
+      AddStabilityDependency(maps->at(i).handle());
+    }
+    return;
+  }
 
   LOperand* input = instr->value();
   ASSERT(input->IsRegister());
   Register reg = ToRegister(input);
 
   DeferredCheckMaps* deferred = NULL;
-  if (instr->hydrogen()->has_migration_target()) {
+  if (instr->hydrogen()->HasMigrationTarget()) {
     deferred = new(zone()) DeferredCheckMaps(this, instr, reg);
     __ bind(deferred->check_maps());
   }
@@ -5035,7 +5041,7 @@ void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
 
   Handle<Map> map = maps->at(maps->size() - 1).handle();
   __ CompareMap(reg, map);
-  if (instr->hydrogen()->has_migration_target()) {
+  if (instr->hydrogen()->HasMigrationTarget()) {
     __ j(not_equal, deferred->entry());
   } else {
     DeoptimizeIf(not_equal, instr->environment());