Update to the Fortran 2023 standard. Reorganize some code to reflect the
dropping of dialect support in the previous commit. Minor improvements.
closes: #13712
Signed-off-by: Ajit-Thakkar <142174202+Ajit-Thakkar@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>