+/**
+ * Move Casts of the same type through a Phi node, i.e.
+ * Phi(Cast(type, x_0), ..., Cast(type, x_n)) -> Cast(type, Phi(x_0, ..., x_n))
+ *
+ * @param phi the Phi node
+ *
+ * @return 1 if Cast's where moved
+ */
+static int concretize_Phi_type(ir_node *phi)