[Bug fortran/25829] [F03] Asynchronous IO support

["tkoenig at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25829

--- Comment #28 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
(In reply to Nicolas Koenig from comment #27)

> program main
>     implicit none
>     open (10, file='foo.dat', asynchronous='yes')
>     call s()
>     close(10)
> contains
>     subroutine s()
>         integer, dimension (3)::i !presumably on the stack
>         i = [0, 1]
>         write(10,*) i
>         !Now the stack frame is dropped and the pointer that previously
>         !pointed to the array now points to nowhere, but it is still enqueued
>     end subroutine
> end program

This program is illegal (J3/09-007r3, 9.6.4.1, paragraph 4),
so you do not have to do anything about it.

An interesting case is mixing of synchronous and
asynchronous I/O for the same unit, which is permitted.
I think this is like an implicit WAIT, same as a BACKSPACE,
FLUSH, ...