pgsql: Teach in-tree getopt_long() to move non-options to the end of ar

Teach in-tree getopt_long() to move non-options to the end of argv.

Unlike the other implementations of getopt_long() I could find, the
in-tree implementation does not reorder non-options to the end of
argv.  Instead, it returns -1 as soon as the first non-option is
found, even if there are other options listed afterwards.  By
moving non-options to the end of argv, getopt_long() can parse all
specified options and return -1 when only non-options remain.
This quirk is periodically missed by hackers (e.g., 869aa40a27,
ffd398021c, and d9ddc50baf).  This commit introduces the
aforementioned non-option reordering behavior to the in-tree
getopt_long() implementation.

Special thanks to Noah Misch for his help verifying behavior on
AIX.

Reviewed-by: Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/20230609232257.GA121461%40nathanxps13

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/411b720343005597d042fc1736ce9a3a3ee8a1fe

Modified Files
--------------
src/bin/scripts/t/040_createuser.pl | 10 ++++---
src/port/getopt_long.c              | 53 ++++++++++++++++++++++++++-----------
2 files changed, 44 insertions(+), 19 deletions(-)