create-diff-object: Add is_special_section() helper function

create-diff-object: Add is_special_section() helper function

This function determines, based on the given section name, if the
sections belongs to the special sections category.

Add more special sections to special_sections[] along with a new
undefined_group_size() helper function returning 0 (undefined).
New special sections are: .altinstr_replacement.

Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Andra-Irina Paraschiv <andraprs@amazon.com>
Reviewed-by: Bjoern Doebel <doebel@amazon.de>
Reviewed-by: Norbert Manthey <nmanthey@amazon.de>