[in-place weak refs prework] Remove dead FeedbackVector::copy.

BUG=v8:7308

Change-Id: I55400096095619e2995a50adadf93253fc95d34c
Reviewed-on: https://chromium-review.googlesource.com/1034057Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52880}

src/feedback-vector.cc

@@ -283,19 +283,6 @@ Handle<FeedbackVector> FeedbackVector::New(Isolate* isolate,
   return result;
 }
 
-// static
-Handle<FeedbackVector> FeedbackVector::Copy(Isolate* isolate,
-                                            Handle<FeedbackVector> vector) {
-  Handle<FeedbackVector> result;
-  result = Handle<FeedbackVector>::cast(
-      isolate->factory()->CopyFixedArray(Handle<FixedArray>::cast(vector)));
-  if (!isolate->is_best_effort_code_coverage() ||
-      isolate->is_collecting_type_profile()) {
-    AddToVectorsForProfilingTools(isolate, result);
-  }
-  return result;
-}
-
 // static
 void FeedbackVector::AddToVectorsForProfilingTools(
     Isolate* isolate, Handle<FeedbackVector> vector) {

src/feedback-vector.h

@@ -214,9 +214,6 @@ class FeedbackVector : public HeapObject {
   V8_EXPORT_PRIVATE static Handle<FeedbackVector> New(
       Isolate* isolate, Handle<SharedFunctionInfo> shared);
 
-  static Handle<FeedbackVector> Copy(Isolate* isolate,
-                                     Handle<FeedbackVector> vector);
-
 #define DEFINE_SLOT_KIND_PREDICATE(Name) \
   bool Name(FeedbackSlot slot) const { return Name##Kind(GetKind(slot)); }