[in-place weak refs] Remove DeoptimizationData::WeakCellCache

It's now unused.

BUG=v8:7308

Change-Id: I301b83fde1d941d5d535922a1174d017186b82ce
Reviewed-on: https://chromium-review.googlesource.com/1169017Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55020}

src/objects-inl.h

@@ -2061,7 +2061,6 @@ DEFINE_DEOPT_ELEMENT_ACCESSORS(LiteralArray, FixedArray)
 DEFINE_DEOPT_ELEMENT_ACCESSORS(OsrBytecodeOffset, Smi)
 DEFINE_DEOPT_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
 DEFINE_DEOPT_ELEMENT_ACCESSORS(OptimizationId, Smi)
-DEFINE_DEOPT_ELEMENT_ACCESSORS(WeakCellCache, Object)
 DEFINE_DEOPT_ELEMENT_ACCESSORS(InliningPositions, PodArray<InliningPosition>)
 
 DEFINE_DEOPT_ENTRY_ACCESSORS(BytecodeOffsetRaw, Smi)

src/objects.cc

@@ -14599,29 +14599,6 @@ bool Code::IsIsolateIndependent(Isolate* isolate) {
   return is_process_independent;
 }
 
-Handle<WeakCell> Code::WeakCellFor(Handle<Code> code) {
-  DCHECK(code->kind() == OPTIMIZED_FUNCTION);
-  WeakCell* raw_cell = code->CachedWeakCell();
-  if (raw_cell != nullptr) {
-    return Handle<WeakCell>(raw_cell, code->GetIsolate());
-  }
-  Handle<WeakCell> cell = code->GetIsolate()->factory()->NewWeakCell(code);
-  DeoptimizationData::cast(code->deoptimization_data())
-      ->SetWeakCellCache(*cell);
-  return cell;
-}
-
-WeakCell* Code::CachedWeakCell() {
-  DCHECK(kind() == OPTIMIZED_FUNCTION);
-  Object* weak_cell_cache =
-      DeoptimizationData::cast(deoptimization_data())->WeakCellCache();
-  if (weak_cell_cache->IsWeakCell()) {
-    DCHECK(this == WeakCell::cast(weak_cell_cache)->value());
-    return WeakCell::cast(weak_cell_cache);
-  }
-  return nullptr;
-}
-
 bool Code::Inlines(SharedFunctionInfo* sfi) {
   // We can only check for inlining for optimized code.
   DCHECK(is_optimized_code());

src/objects/code.h

@@ -356,9 +356,6 @@ class Code : public HeapObject, public NeverReadOnlySpaceObject {
 
   static inline bool IsWeakObjectInOptimizedCode(Object* object);
 
-  static Handle<WeakCell> WeakCellFor(Handle<Code> code);
-  WeakCell* CachedWeakCell();
-
   // Return true if the function is inlined in the code.
   bool Inlines(SharedFunctionInfo* sfi);
 
@@ -837,9 +834,8 @@ class DeoptimizationData : public FixedArray {
   static const int kOsrPcOffsetIndex = 4;
   static const int kOptimizationIdIndex = 5;
   static const int kSharedFunctionInfoIndex = 6;
-  static const int kWeakCellCacheIndex = 7;
-  static const int kInliningPositionsIndex = 8;
-  static const int kFirstDeoptEntryIndex = 9;
+  static const int kInliningPositionsIndex = 7;
+  static const int kFirstDeoptEntryIndex = 8;
 
   // Offsets of deopt entry elements relative to the start of the entry.
   static const int kBytecodeOffsetRawOffset = 0;
@@ -859,7 +855,6 @@ class DeoptimizationData : public FixedArray {
   DECL_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
   DECL_ELEMENT_ACCESSORS(OptimizationId, Smi)
   DECL_ELEMENT_ACCESSORS(SharedFunctionInfo, Object)
-  DECL_ELEMENT_ACCESSORS(WeakCellCache, Object)
   DECL_ELEMENT_ACCESSORS(InliningPositions, PodArray<InliningPosition>)
 
 #undef DECL_ELEMENT_ACCESSORS