Return value of correct width for dynamic array out-of-bound access

Commit e1870acfac ("Return the correct value when a queue or darray
references an undefined element") added support for specifying the width of
the vector elements stored in a queue or dynamic array, so that an
out-of-bounds access can create a word with the right width.

To get the element width of a queue or dynamic array it uses the
`packed_width()` method. But this method is only implemented for
`netqueue_t` and returns always 1 for dynamic arrays. As a result
out-of-bounds access on a dynamic array will push a vector of the wrong
width onto the stack if the vector element is wider than 1 bit. This will
usually trigger an assert in vvp.

Fix this by moving the `packed_width()` method implementation from
`netqueue_t` to its base class `netdarray_t` so that it works for all types
of dynamic arrays.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

netdarray.h

@@ -36,6 +36,9 @@ class netdarray_t : public netarray_t {
 	// A dynamic array may have a type that is signed.
       inline bool get_signed() const { return element_type()->get_signed(); }
 
+	// Use the packed width to pass the element width
+      long packed_width() const { return element_type()->packed_width(); }
+
 	// 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.

netqueue.h

@@ -38,9 +38,6 @@ class netqueue_t : public netdarray_t {
 	// IVL_VT_QUEUE for queues.
       ivl_variable_type_t base_type() const;
 
-	// Use the packed width to pass the element width
-      long packed_width(void) const { return element_type()->packed_width(); }
-
       long max_idx(void) const { return max_idx_; }
 
       std::ostream& debug_dump(std::ostream&) const;