[turbofan] Introduce a dedicated ConvertTaggedHoleToUndefined operator.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 46f114f11d8869c7e262fda444ff7c9e6793a8f1..e7d7eedc2f49abf6eaff07a14c9180e5a602bb93 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -2609,6 +2609,8 @@ void Heap::CreateInitialObjects() {
 
   set_nan_value(*factory->NewHeapNumber(
       std::numeric_limits<double>::quiet_NaN(), IMMUTABLE, TENURED));
+  set_hole_nan_value(*factory->NewHeapNumber(bit_cast<double>(kHoleNanInt64),
+                                             IMMUTABLE, TENURED));
   set_infinity_value(*factory->NewHeapNumber(V8_INFINITY, IMMUTABLE, TENURED));
   set_minus_infinity_value(
       *factory->NewHeapNumber(-V8_INFINITY, IMMUTABLE, TENURED));
@@ -2629,7 +2631,7 @@ void Heap::CreateInitialObjects() {
 
   // Initialize the_hole_value.
   Oddball::Initialize(isolate(), factory->the_hole_value(), "hole",
-                      handle(Smi::FromInt(-1), isolate()), "undefined",
+                      factory->hole_nan_value(), "undefined",
                       Oddball::kTheHole);
 
   // Initialize the true_value.