[turbofan] Treat PREMONOMORPHIC like UNINITIALIZED.

src/compiler/js-native-context-specialization.cc

Index: src/compiler/js-native-context-specialization.cc
diff --git a/src/compiler/js-native-context-specialization.cc b/src/compiler/js-native-context-specialization.cc
index 7fcbf626557ac546913b3237c5e645aea1a53792..86f7924b2be8883496b0c1cd65f03cfef378da44 100644
--- a/src/compiler/js-native-context-specialization.cc
+++ b/src/compiler/js-native-context-specialization.cc
@@ -328,7 +328,7 @@ Reduction JSNativeContextSpecialization::ReduceNamedAccessFromNexus(
   Node* const effect = NodeProperties::GetEffectInput(node);
 
   // Check if the {nexus} reports type feedback for the IC.
-  if (nexus.IsUninitialized()) {
+  if (nexus.IsUninitialized() || nexus.IsPremonomorphic()) {
     if ((flags() & kDeoptimizationEnabled) &&
         (flags() & kBailoutOnUninitialized)) {
       return ReduceSoftDeoptimize(
@@ -689,7 +689,7 @@ Reduction JSNativeContextSpecialization::ReduceKeyedAccess(
   Node* const effect = NodeProperties::GetEffectInput(node);
 
   // Check if the {nexus} reports type feedback for the IC.
-  if (nexus.IsUninitialized()) {
+  if (nexus.IsUninitialized() || nexus.IsPremonomorphic()) {
     if ((flags() & kDeoptimizationEnabled) &&
         (flags() & kBailoutOnUninitialized)) {
       return ReduceSoftDeoptimize(