* testsuite/ld-elfcomm/elfcomm.exp (test_sort_common): Test the
ascending/descending argument to the --sort-common command line
option.
* testsuite/ld-elfcomm/sort-common.s: New file.
* ld.h (enum sort_order): New.
* ldlang.c (lang_check: Fix comment.
(lang_common): Sort commons in ascending or descending order.
(lang_one_common): Likewise.
* lexsup.c (ld_options): Have --sort-common take an option
argument.
(parse_args): Handle argument to --sort-common.
* ld.texinfo (--sort-common): Document new optional argument.
* NEWS: Mention new feature.
