Remove unused ValueObjectDynamicValue::SetOwningSP & backing ivar

[jingham]

Summary

This owning_sp has no uses and the ValueObjectDynamicValue already tracks
its ownership through the parent it is passed when made. I can't
find any vestiges of the use of this API, maybe it was from some
earlier design?

Resetting the backing ivar was the only job the destructor did, so I
set that to default as well.

[clayborg]

I am sure you have checked the Swift codebase as well for any uses. If so LGTM.

lldb/include/lldb/Core/ValueObjectDynamicValue.h

 class DataExtractor;
 class Declaration;
 class Status;
 
 /// A ValueObject that represents memory at a given address, viewed as some
 /// set lldb type.
 class ValueObjectDynamicValue : public ValueObject {
 public:
-  ~ValueObjectDynamicValue() override;
+  ~ValueObjectDynamicValue() = default;
 
   llvm::Optional<uint64_t> GetByteSize() override;
 
   ConstString GetTypeName() override;
 
   ConstString GetQualifiedTypeName() override;
 
   ConstString GetDisplayTypeName() override;
public:
   }
 
   const ValueObject *GetParent() const override {
     return ((m_parent != nullptr) ? m_parent->GetParent() : nullptr);
   }
 
   lldb::ValueObjectSP GetStaticValue() override { return m_parent->GetSP(); }
 
-  void SetOwningSP(lldb::ValueObjectSP &owning_sp) {
-    if (m_owning_valobj_sp == owning_sp)
-      return;
-
-    assert(m_owning_valobj_sp.get() == nullptr);
-    m_owning_valobj_sp = owning_sp;
-  }
-
   bool SetValueFromCString(const char *value_str, Status &error) override;
 
   bool SetData(DataExtractor &data, Status &error) override;
 
   TypeImpl GetTypeImpl() override;
 
   lldb::VariableSP GetVariable() override {
     return m_parent ? m_parent->GetVariable() : nullptr;
protected:
   }
 
   bool HasDynamicValueTypeInfo() override { return true; }
 
   CompilerType GetCompilerTypeImpl() override;
 
   Address m_address; ///< The variable that this value object is based upon
   TypeAndOrName m_dynamic_type_info; // We can have a type_sp or just a name
-  lldb::ValueObjectSP m_owning_valobj_sp;
   lldb::DynamicValueType m_use_dynamic;
   TypeImpl m_type_impl;
 
 private:
   friend class ValueObject;
   friend class ValueObjectConstResult;
   ValueObjectDynamicValue(ValueObject &parent,
                           lldb::DynamicValueType use_dynamic);

lldb/source/Core/ValueObjectDynamicValue.cpp

 
 ValueObjectDynamicValue::ValueObjectDynamicValue(
     ValueObject &parent, lldb::DynamicValueType use_dynamic)
     : ValueObject(parent), m_address(), m_dynamic_type_info(),
       m_use_dynamic(use_dynamic) {
   SetName(parent.GetName());
 }
 
-ValueObjectDynamicValue::~ValueObjectDynamicValue() {
-  m_owning_valobj_sp.reset();
-}
-
 CompilerType ValueObjectDynamicValue::GetCompilerTypeImpl() {
   const bool success = UpdateValueIfNeeded(false);
   if (success) {
     if (m_dynamic_type_info.HasType())
       return m_value.GetCompilerType();
     else
       return m_parent->GetCompilerType();
   }