[handles] Remove singleton eternal handles

This is currently dead code as intl no longer uses this to reset the
cache. Intl will use a different caching strategy in the future.

Bug: v8:5751
Change-Id: I343fa8afe5069cb7228106b3cd355d004aed199f
Reviewed-on: https://chromium-review.googlesource.com/c/1319766Reviewed-by: Frank Tang <ftang@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57311}

src/api.cc

@@ -6844,17 +6844,6 @@ void v8::Date::DateTimeConfigurationChangeNotification(Isolate* isolate) {
   LOG_API(i_isolate, Date, DateTimeConfigurationChangeNotification);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
   i_isolate->date_cache()->ResetDateCache();
-  if (!i_isolate->eternal_handles()->Exists(
-          i::EternalHandles::DATE_CACHE_VERSION)) {
-    return;
-  }
-  i::Handle<i::FixedArray> date_cache_version =
-      i::Handle<i::FixedArray>::cast(i_isolate->eternal_handles()->GetSingleton(
-          i::EternalHandles::DATE_CACHE_VERSION));
-  DCHECK_EQ(1, date_cache_version->length());
-  CHECK(date_cache_version->get(0)->IsSmi());
-  date_cache_version->set(
-      0, i::Smi::FromInt(i::Smi::ToInt(date_cache_version->get(0)) + 1));
 }
 
 

src/global-handles.cc

@@ -1079,12 +1079,7 @@ void GlobalHandles::Print() {
 
 void GlobalHandles::TearDown() {}
 
-EternalHandles::EternalHandles() : size_(0) {
-  for (unsigned i = 0; i < arraysize(singleton_handles_); i++) {
-    singleton_handles_[i] = kInvalidIndex;
-  }
-}
-
+EternalHandles::EternalHandles() : size_(0) {}
 
 EternalHandles::~EternalHandles() {
   for (Address* block : blocks_) delete[] block;

src/global-handles.h

@@ -257,12 +257,6 @@ class GlobalHandles::PendingPhantomCallback {
 
 class EternalHandles {
  public:
-  enum SingletonHandle {
-    DATE_CACHE_VERSION,
-
-    NUMBER_OF_SINGLETON_HANDLES
-  };
-
   EternalHandles();
   ~EternalHandles();
 
@@ -276,25 +270,6 @@ class EternalHandles {
     return Handle<Object>(GetLocation(index));
   }
 
-  // Grab the handle for an existing SingletonHandle.
-  inline Handle<Object> GetSingleton(SingletonHandle singleton) {
-    DCHECK(Exists(singleton));
-    return Get(singleton_handles_[singleton]);
-  }
-
-  // Checks whether a SingletonHandle has been assigned.
-  inline bool Exists(SingletonHandle singleton) {
-    return singleton_handles_[singleton] != kInvalidIndex;
-  }
-
-  // Assign a SingletonHandle to an empty slot and returns the handle.
-  Handle<Object> CreateSingleton(Isolate* isolate,
-                                 Object* object,
-                                 SingletonHandle singleton) {
-    Create(isolate, object, &singleton_handles_[singleton]);
-    return Get(singleton_handles_[singleton]);
-  }
-
   // Iterates over all handles.
   void IterateAllRoots(RootVisitor* visitor);
   // Iterates over all handles which might be in new space.
@@ -318,7 +293,6 @@ class EternalHandles {
   int size_;
   std::vector<Address*> blocks_;
   std::vector<int> new_space_indices_;
-  int singleton_handles_[NUMBER_OF_SINGLETON_HANDLES];
 
   DISALLOW_COPY_AND_ASSIGN(EternalHandles);
 };