generate ALIGN_TO_x_BYTES instructions if the element has the align_x flag

Pick up change from Samba:

    commit 93f262ee6d162bf007b79d2daf9de6c49c6163d1
    Author: Matthieu Patou <mat@matws.net>
    Date:   Fri Oct 18 00:04:28 2013 -0700

    pidl-wireshark: generate ALIGN_TO_x_BYTES instructions if the element has the align_x flag

Change-Id: I865eae69ea7a8200630d3ad69bda9ac7b1c12255
Reviewed-on: https://code.wireshark.org/review/5099
Reviewed-by: Guy Harris <guy@alum.mit.edu>