Remove unused ThreadedListZoneEntry and don't include zone.h to utils.h

Bug: v8:7754
Change-Id: Id7701375897f6f3cfac7327404751b43cfdb221c
Reviewed-on: https://chromium-review.googlesource.com/1118888Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54252}

src/compiler/machine-operator.h

@@ -10,6 +10,7 @@
 #include "src/globals.h"
 #include "src/machine-type.h"
 #include "src/utils.h"
+#include "src/zone/zone.h"
 
 namespace v8 {
 namespace internal {

src/utils.h

@@ -21,7 +21,6 @@
 #include "src/base/v8-fallthrough.h"
 #include "src/globals.h"
 #include "src/vector.h"
-#include "src/zone/zone.h"
 
 #if defined(V8_OS_AIX)
 #include <fenv.h>  // NOLINT(build/c++11)
@@ -1805,21 +1804,6 @@ class ThreadedList final {
   DISALLOW_COPY_AND_ASSIGN(ThreadedList);
 };
 
-// Can be used to create a threaded list of |T|.
-template <typename T>
-class ThreadedListZoneEntry final : public ZoneObject {
- public:
-  explicit ThreadedListZoneEntry(T value) : value_(value), next_(nullptr) {}
-
-  T value() { return value_; }
-  ThreadedListZoneEntry<T>** next() { return &next_; }
-
- private:
-  T value_;
-  ThreadedListZoneEntry<T>* next_;
-  DISALLOW_COPY_AND_ASSIGN(ThreadedListZoneEntry);
-};
-
 V8_EXPORT_PRIVATE bool PassesFilter(Vector<const char> name,
                                     Vector<const char> filter);
 

src/wasm/wasm-interpreter.h

@@ -10,9 +10,6 @@
 #include "src/zone/zone-containers.h"
 
 namespace v8 {
-namespace base {
-class AccountingAllocator;
-}
 
 namespace internal {
 class WasmInstanceObject;