Test override secondary base Itanium.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

tests/CSharp/CSharp.Tests.cs

@@ -102,6 +102,24 @@ public unsafe class CSharpTests : GeneratorTestFixture
 #pragma warning restore 0219
     }
 
+    class MyClass : Der
+    {
+        public override int F => 10;
+    }
+
+    [Test]
+    public void TestDer()
+    {
+        using (var der = new MyClass())
+        {
+            using (var hasDer = new HasDer())
+            {
+                hasDer.SetDer(der);
+                Assert.That(hasDer.CallDer(), Is.EqualTo(10));
+            }
+        }
+    }
+
     [Test]
     public void TestReturnCharPointer()
     {

tests/CSharp/CSharp.cpp

@@ -865,6 +865,50 @@ AbstractWithProperty::~AbstractWithProperty()
 {
 }
 
+SB::SB()
+{
+}
+
+SB::~SB()
+{
+}
+
+int SB::f()
+{
+    return 5;
+}
+
+Der::Der()
+{
+}
+
+Der::~Der()
+{
+}
+
+int Der::derf()
+{
+    return 55;
+}
+
+HasDer::HasDer()
+{
+}
+
+HasDer::~HasDer()
+{
+}
+
+void HasDer::setDer(Der* value)
+{
+    der = value;
+}
+
+int HasDer::callDer()
+{
+    return der->f();
+}
+
 IgnoredType PropertyWithIgnoredType::ignoredType()
 {
     return _ignoredType;

tests/CSharp/CSharp.h

@@ -537,6 +537,33 @@ class DLL_API IgnoredTypeInheritingNonIgnoredWithNoEmptyCtor : public P
 {
 };
 
+class DLL_API SB
+{
+public:
+    SB();
+    ~SB();
+    virtual int f();
+};
+
+class DLL_API Der : public Foo, public SB
+{
+public:
+    Der();
+    ~Der();
+    virtual int derf();
+};
+
+class DLL_API HasDer
+{
+public:
+    HasDer();
+    ~HasDer();
+    void setDer(Der* value);
+    int callDer();
+private:
+    Der* der = 0;
+};
+
 class DLL_API PropertyWithIgnoredType
 {
 public: