[objects] Remove unused Code::ic_age field.

R=mvstanton@chromium.org

Change-Id: Ic8276eb6c282032a81d40c47409ead31d11565b7
Reviewed-on: https://chromium-review.googlesource.com/549302Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46256}

src/factory.cc

@@ -1726,7 +1726,6 @@ Handle<Code> Factory::NewCode(const CodeDesc& desc,
   // The code object has not been fully initialized yet.  We rely on the
   // fact that no allocation will happen from this point on.
   DisallowHeapAllocation no_gc;
-  code->set_ic_age(isolate()->heap()->global_ic_age());
   code->set_instruction_size(desc.instr_size);
   code->set_relocation_info(*reloc_info);
   code->set_flags(flags);

src/heap/heap.cc

@@ -3445,7 +3445,6 @@ AllocationResult Heap::AllocateCode(int object_size, bool immovable) {
   DCHECK(!memory_allocator()->code_range()->valid() ||
          memory_allocator()->code_range()->contains(code->address()) ||
          object_size <= code_space()->AreaSize());
-  code->set_ic_age(global_ic_age_);
   return code;
 }
 

src/objects-inl.h

@@ -5187,9 +5187,6 @@ void Code::set_stub_key(uint32_t key) {
 }
 
 
-INT_ACCESSORS(Code, ic_age, kICAgeOffset)
-
-
 byte* Code::instruction_start()  {
   return FIELD_ADDR(this, kHeaderSize);
 }

src/objects.h

@@ -3639,11 +3639,6 @@ class Code: public HeapObject {
   // Note that storage for this field is overlapped with typefeedback_info.
   DECL_ACCESSORS(next_code_link, Object)
 
-  // [ic_age]: Inline caching age: the value of the Heap::global_ic_age
-  // at the moment when this object was created.
-  inline void set_ic_age(int count);
-  inline int ic_age() const;
-
   // [prologue_offset]: Offset of the function prologue, used for aging
   // FUNCTIONs and OPTIMIZED_FUNCTIONs.
   inline int prologue_offset() const;
@@ -3998,8 +3993,7 @@ class Code: public HeapObject {
       kSourcePositionTableOffset + kPointerSize;
   static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset + kPointerSize;
   static const int kInstructionSizeOffset = kNextCodeLinkOffset + kPointerSize;
-  static const int kICAgeOffset = kInstructionSizeOffset + kIntSize;
-  static const int kFlagsOffset = kICAgeOffset + kIntSize;
+  static const int kFlagsOffset = kInstructionSizeOffset + kIntSize;
   static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
   static const int kKindSpecificFlags2Offset =
       kKindSpecificFlags1Offset + kIntSize;