Symbols for type cells.

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 082a480ee85937092785c2f8fcaf5a4c42fd25ef..03b53b3d36341f4473083d91be8d9beda2648184 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -3782,8 +3782,9 @@ void LCodeGen::DoCallNew(LCallNew* instr) {
 
   __ Set(rax, instr->arity());
   // No cell in ebx for construct type feedback in optimized code
-  Handle<Object> undefined_value(isolate()->factory()->undefined_value());
-  __ Move(rbx, undefined_value);
+  Handle<Object> megamorphic_symbol =
+      TypeFeedbackInfo::MegamorphicSentinel(isolate());
+  __ Move(rbx, megamorphic_symbol);
   CallConstructStub stub(NO_CALL_FUNCTION_FLAGS);
   CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
 }
@@ -3795,7 +3796,7 @@ void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
   ASSERT(ToRegister(instr->result()).is(rax));
 
   __ Set(rax, instr->arity());
-  __ Move(rbx, factory()->undefined_value());
+  __ Move(rbx, TypeFeedbackInfo::MegamorphicSentinel(isolate()));
   ElementsKind kind = instr->hydrogen()->elements_kind();
   AllocationSiteOverrideMode override_mode =
       (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE)