Make interpreter handle typecast in pointer expr

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

Author: romainbrenguier

src/goto-programs/interpreter_evaluate.cpp

@@ -18,6 +18,7 @@ Author: Daniel Kroening, kroening@kroening.com
 #include <util/string_container.h>
 
 #include <langapi/language_util.h>
+#include <util/expr_util.h>
 
 /// Reads a memory address and loads it into the `dest` variable.
 /// Marks cell as `READ_BEFORE_WRITTEN` if cell has never been written.
@@ -347,12 +348,13 @@ void interpretert::evaluate(
     {
       if(expr.has_operands())
       {
-        if(expr.op0().id() == ID_address_of)
+        const exprt &object = skip_typecast(expr.op0());
+        if(object.id() == ID_address_of)
         {
-          evaluate(expr.op0(), dest);
+          evaluate(object, dest);
           return;
         }
-        else if(const auto i = numeric_cast<mp_integer>(expr.op0()))
+        else if(const auto i = numeric_cast<mp_integer>(object))
         {
           dest.push_back(*i);
           return;