create-diff-object: Add new entries to special sections array
Handle .livepatch.hooks* and .altinstr_replacement sections as the
special sections with assigned group_size resolution function.
By default each .livepatch.hooks* sections' entry is 8 bytes long (a
pointer). The .altinstr_replacement section has undefined group_size.
Allow to specify different .livepatch.hooks* section entry size using
shell environment variable HOOK_STRUCT_SIZE.