Stop overallocating feedback vector slots.

src/type-info.cc

Index: src/type-info.cc
diff --git a/src/type-info.cc b/src/type-info.cc
index a813311bf149c2888d0533c7a70d1851d63c0726..1b7bc8e8b614407d9acf0bd426f3ef830e5eccec 100644
--- a/src/type-info.cc
+++ b/src/type-info.cc
@@ -106,13 +106,15 @@ InlineCacheState TypeFeedbackOracle::LoadInlineCacheState(TypeFeedbackId id) {
 
 InlineCacheState TypeFeedbackOracle::LoadInlineCacheState(
     FeedbackVectorICSlot slot) {
-  Code::Kind kind = feedback_vector_->GetKind(slot);
-  if (kind == Code::LOAD_IC) {
-    LoadICNexus nexus(feedback_vector_, slot);
-    return nexus.StateFromFeedback();
-  } else if (kind == Code::KEYED_LOAD_IC) {
-    KeyedLoadICNexus nexus(feedback_vector_, slot);
-    return nexus.StateFromFeedback();
+  if (!slot.IsInvalid()) {
+    Code::Kind kind = feedback_vector_->GetKind(slot);
+    if (kind == Code::LOAD_IC) {
+      LoadICNexus nexus(feedback_vector_, slot);
+      return nexus.StateFromFeedback();
+    } else if (kind == Code::KEYED_LOAD_IC) {
+      KeyedLoadICNexus nexus(feedback_vector_, slot);
+      return nexus.StateFromFeedback();
+    }
   }
 
   // If we can't find an IC, assume we've seen *something*, but we don't know
@@ -331,9 +333,11 @@ void TypeFeedbackOracle::PropertyReceiverTypes(FeedbackVectorICSlot slot,
                                                Handle<Name> name,
                                                SmallMapList* receiver_types) {
   receiver_types->Clear();
-  LoadICNexus nexus(feedback_vector_, slot);
-  Code::Flags flags = Code::ComputeHandlerFlags(Code::LOAD_IC);
-  CollectReceiverTypes(&nexus, name, flags, receiver_types);
+  if (!slot.IsInvalid()) {
+    LoadICNexus nexus(feedback_vector_, slot);
+    Code::Flags flags = Code::ComputeHandlerFlags(Code::LOAD_IC);
+    CollectReceiverTypes(&nexus, name, flags, receiver_types);
+  }
 }
 
 
@@ -341,10 +345,15 @@ void TypeFeedbackOracle::KeyedPropertyReceiverTypes(
     FeedbackVectorICSlot slot, SmallMapList* receiver_types, bool* is_string,
     IcCheckType* key_type) {
   receiver_types->Clear();
-  KeyedLoadICNexus nexus(feedback_vector_, slot);
-  CollectReceiverTypes<FeedbackNexus>(&nexus, receiver_types);
-  *is_string = HasOnlyStringMaps(receiver_types);
-  *key_type = nexus.FindFirstName() != NULL ? PROPERTY : ELEMENT;
+  if (slot.IsInvalid()) {
+    *is_string = false;
+    *key_type = ELEMENT;
+  } else {
+    KeyedLoadICNexus nexus(feedback_vector_, slot);
+    CollectReceiverTypes<FeedbackNexus>(&nexus, receiver_types);
+    *is_string = HasOnlyStringMaps(receiver_types);
+    *key_type = nexus.FindFirstName() != NULL ? PROPERTY : ELEMENT;
+  }
 }