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

src/arm/assembler-arm.h

Index: src/arm/assembler-arm.h
diff --git a/src/arm/assembler-arm.h b/src/arm/assembler-arm.h
index 49881cfd0d2ffb24f8421d54b1a71dbfce390ae2..3deb3afb4e2087af8ccc44e44a0a42ff746a7422 100644
--- a/src/arm/assembler-arm.h
+++ b/src/arm/assembler-arm.h
@@ -608,6 +608,7 @@ class Operand BASE_EMBEDDED {
   int shift_imm_;  // valid if rm_ != no_reg && rs_ == no_reg
   int32_t imm32_;  // valid if rm_ == no_reg
   RelocInfo::Mode rmode_;
+  bool weak_in_optimized_code_;
 
   friend class Assembler;
 };
@@ -713,12 +714,13 @@ class ConstantPoolBuilder BASE_EMBEDDED {
   void AddEntry(Assembler* assm, const RelocInfo& rinfo);
   void Relocate(int pc_delta);
   bool IsEmpty();
-  MaybeObject* Allocate(Heap* heap);
+  MaybeObject* Allocate(Heap* heap, bool has_weak_pointers);
   void Populate(Assembler* assm, ConstantPoolArray* constant_pool);
 
   inline int count_of_64bit() const { return count_of_64bit_; }
   inline int count_of_code_ptr() const { return count_of_code_ptr_; }
   inline int count_of_heap_ptr() const { return count_of_heap_ptr_; }
+  inline int count_of_weak_ptr() const { return count_of_weak_ptr_; }
   inline int count_of_32bit() const { return count_of_32bit_; }
 
  private:
@@ -732,6 +734,7 @@ class ConstantPoolBuilder BASE_EMBEDDED {
   int count_of_64bit_;
   int count_of_code_ptr_;
   int count_of_heap_ptr_;
+  int count_of_weak_ptr_;
   int count_of_32bit_;
 };
 
@@ -1497,7 +1500,7 @@ class Assembler : public AssemblerBase {
   void CheckConstPool(bool force_emit, bool require_jump);
 
   // Allocate a constant pool of the correct size for the generated code.
-  MaybeObject* AllocateConstantPool(Heap* heap);
+  MaybeObject* AllocateConstantPool(Heap* heap, bool has_weak_pointers);
 
   // Generate the constant pool for the generated code.
   void PopulateConstantPool(ConstantPoolArray* constant_pool);