Make interpreter handle typecast in pointer expr

The interpreter would fail to interpret expressions of type pointer
which contained typecast. This fixes it by following inside the typecast
that are encountered.

Author: romainbrenguier

src/goto-programs/interpreter_evaluate.cpp

@@ -347,12 +347,19 @@ void interpretert::evaluate(
     {
       if(expr.has_operands())
       {
-        if(expr.op0().id() == ID_address_of)
+        auto object_ref = std::ref(expr.op0());
+        while(const auto typecast =
+                expr_try_dynamic_cast<typecast_exprt>(object_ref.get()))
         {
-          evaluate(expr.op0(), dest);
+          object_ref = std::ref(typecast->op0());
+        }
+
+        if(object_ref.get().id() == ID_address_of)
+        {
+          evaluate(object_ref.get(), dest);
           return;
         }
-        else if(const auto i = numeric_cast<mp_integer>(expr.op0()))
+        else if(const auto i = numeric_cast<mp_integer>(object_ref))
         {
           dest.push_back(*i);
           return;