Correcting initialization of floatbv_typecast_exprt

This was calling initializer of binary_exprt that resize the operators
to size 2 without filling them up, which resulted in 4 operands
instead of 2 for floatbv_typecast_exprt, with two of them being empty.

Author: romainbrenguier

src/util/std_expr.h

@@ -1790,9 +1790,8 @@ class floatbv_typecast_exprt:public binary_exprt
   floatbv_typecast_exprt(
     const exprt &op,
     const exprt &rounding,
-    const typet &_type):binary_exprt(ID_floatbv_typecast, _type)
+    const typet &_type):binary_exprt(op, ID_floatbv_typecast, rounding, _type)
   {
-    copy_to_operands(op, rounding);
   }
 
   exprt &op()