statements like as valid:
use INTRINSIC, ISO_FORTRAN_ENV
Incidentally, you can find the final draft of F2003 (which differs very little from the published standard) at http://www.j3-fortran.org/doc/year/04/04-007.pdf
Actually, you got the syntax slightly wrong (sorry for not noticing it right away).
The standard (and from my reading of the ibm docs it seems that they agree with the standard) specifices the use statement as
use [[, module-nature] ::] module-name [etc...]
where module-nature is either intrinsic or non_intrinsic. That is, if module-nature is specified the ',' and '::' are mandatory, so the statement in comment #1 must be of the form
use, intrinsic :: iso_fortran_env
It's an enhancement (and actually, it's being worked on).
*** Bug 29643 has been marked as a duplicate of this bug. ***
I think that the keywords patch and rejects valid are both incorrect for this PR - it's an enhancement, plain and simple.
Fixed on mainline (rev. 118930)