Support weak heap references in the ConstantPool to support IsWeakObjectInOptimizedCode objects.

test/cctest/test-constantpool.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 
 // Test constant pool array code.
 
 #include "v8.h"
 
 #include "factory.h"
 #include "objects.h"
 #include "cctest.h"
 
@@ skipping 10 matching lines @@
 
 
 TEST(ConstantPool) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   Heap* heap = isolate->heap();
   Factory* factory = isolate->factory();
   v8::HandleScope scope(context->GetIsolate());
 
   // Check construction.
-  Handle<ConstantPoolArray> array = factory->NewConstantPoolArray(3, 1, 2, 1);
+  Handle<ConstantPoolArray> array =
+      factory->NewConstantPoolArray(3, 1, 2, 0, 1);
   CHECK_EQ(array->count_of_int64_entries(), 3);
   CHECK_EQ(array->count_of_code_ptr_entries(), 1);
   CHECK_EQ(array->count_of_heap_ptr_entries(), 2);
+  CHECK_EQ(array->count_of_weak_ptr_entries(), 0);
   CHECK_EQ(array->count_of_int32_entries(), 1);
   CHECK_EQ(array->length(), 7);
   CHECK_EQ(array->first_int64_index(), 0);
   CHECK_EQ(array->first_code_ptr_index(), 3);
   CHECK_EQ(array->first_heap_ptr_index(), 4);
   CHECK_EQ(array->first_int32_index(), 6);
 
   // Check getters and setters.
   int64_t big_number = V8_2PART_UINT64_C(0x12345678, 9ABCDEF0);
   Handle<Object> object = factory->NewHeapNumber(4.0);
@@ skipping 14 matching lines @@
   CHECK_EQ(array->get_int32_entry(6), 50);
 
   // Check pointers are updated on GC.
   Object* old_ptr = array->get_heap_ptr_entry(5);
   CHECK_EQ(*object, old_ptr);
   heap->CollectGarbage(NEW_SPACE);
   Object* new_ptr = array->get_heap_ptr_entry(5);
   CHECK_NE(*object, old_ptr);
   CHECK_EQ(*object, new_ptr);
 }