A dynamic array can have a signed type so pass that correctly

netdarray.h

@@ -1,7 +1,7 @@
 #ifndef IVL_netdarray_H
 #define IVL_netdarray_H
 /*
- * Copyright (c) 2012-2014 Stephen Williams ([email protected])
+ * Copyright (c) 2012-2015 Stephen Williams ([email protected])
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -33,6 +33,9 @@ class netdarray_t : public netarray_t {
 	// IVL_VT_DARRAY for dynamic arrays?
       ivl_variable_type_t base_type() const;
 
+	// A dynamic array may have a type that is signed.
+      inline bool get_signed() const { return element_type()->get_signed(); }
+
 	// This is the base_type() of the element of the array. We
 	// need this in some cases in order to get the base type of
 	// the element, and not the IVL_VT_DARRAY of the array itself.