Ensure LLVM instructions are not deleted

Author: adazem009

src/engine/internal/llvm/llvminstruction.h

@@ -104,6 +104,7 @@ struct LLVMInstruction
         // Linked list
         LLVMInstruction *previous = nullptr;
         LLVMInstruction *next = nullptr;
+        std::shared_ptr<LLVMInstruction> _next; // ensure items are not deleted
 };
 
 } // namespace libscratchcpp

src/engine/internal/llvm/llvminstructionlist.cpp

@@ -55,8 +55,10 @@ void LLVMInstructionList::addInstruction(std::shared_ptr<LLVMInstruction> ins)
 
         ins->previous = nullptr;
         ins->next = nullptr;
+        ins->_next = nullptr;
     } else {
         m_last->next = ins.get();
+        m_last->_next = ins;
         ins->previous = m_last.get();
         m_last = ins;
     }