Fortran: Add language standard selection
Add Fortran_STANDARD
, like (C|CXX)_STANDARD
:
- Fujitsu:
-X
option - GNU:
-std=(f95|f2003|f2008|f2018)
- Intel:
-stand=(f90|f95|f03|f08|f18)
- XL:
-qlanglvl=(77std|90std|90pure|95std|95pure|2003std|2003pure|2008std|2008pure)
(Information originally posted in #22222 (comment 960054)).