OpenACC: a declare link variable used in a routine is rejected ("with 'link' clause used in 'routine' function")

! # Finding (GCC 16.2): a declare link variable used in an OpenACC routine is rejected (Fortran); the reproducer is the catalog
!   program acc34-clause-link
!
! - toolchains: gcc_g90 (GCC 16.2.0, AMD Instinct MI250X gfx90a, Tioga) and gcc_sm80 (GCC 16.2.0,
!   NVIDIA A100 sm_80, wingtip); separate memory only; -O2; OMP_TARGET_OFFLOAD=mandatory
! - build: gfortran -fopenacc -foffload=amdgcn-amdhsa -foffload-options=amdgcn-amdhsa=-march=gfx90a -O2 (gcc_g90);
!   -foffload=nvptx-none -foffload-options=nvptx-none=-march=sm_80 -foffload-options=nvptx-none=-latomic -O2 (gcc_sm80)
! - failure: rejected: with .link. clause used in .routine. function
! - observed: `Error: 'lv' with 'link' clause used in 'routine' function` on both GPUs.
! - expected: compiles; `RESULT ran_on_host=0 check=pass`
! - spec: "The global variable or common block variables may be used in accelerator routines" (OpenACC 3.4 §2.13.3 l.3083-3084), for
!   a variable in a declare link clause; the device copy exists while a data clause holds it (l.3079-3081), here the parallel loop's
!   copyin(lv).
! - GCC 16.2 documentation (libgomp.texi "Enabling OpenACC"): "A complete description of all OpenACC directives accepted may be
!   found in the OpenACC Application Programming Interface manual, version 2.6"; _OPENACC is 201711 (2.6). No list of OpenACC gaps
!   is documented.
! - other families: CCE 19/20/21 compile and run it correctly (MI300A, MI250X); NVHPC 25.11/26.9 compile it and give a wrong answer
!   (not studied here).
! - gate and confirmer: 2 cells (1 gcc_g90, 1 gcc_sm80), each confirmed in the gate's four environments (a-d;
!   results/gcc/gate-tioga/ and gate-wingtip/ verdicts.jsonl); confirmer verdicts (results/gcc/confirm/batch.gcc_*.jsonl):
!   compiler_bug (R11-compile-rejection) 2
! - catalog programs (1): acc34-clause-link
! - legality: the catalog programs are legal by construction (offload.engine.gen, c_gen and acc_gen
!   check every program against the catalog rules and the offload scope as it is built; no
!   compiler). GCC is a compiler under test only: never a legality witness, here or for another
!   family's case (catalog/machines.yaml under_test_only).
! Generated by compliance.gen (OpenACC 3.4, free-form Fortran). Do not edit.
! id: acc34-clause-link
! primary atom: acc.clause.link
! legal: yes
! observable: yes
! ran_on_host: inside the compute region of interest (acc_on_device)
! evidence: construct
! needs: none
! std: f2008
module gen_mod
  use openacc
  implicit none
  integer :: lv(64)
  !$acc declare link(lv)
  contains
    integer function get_lv(k)
      !$acc routine seq
      integer, intent(in) :: k
      get_lv = lv(k)
    end function get_lv
end module gen_mod

program gen_prog
  use openacc, only: acc_device_host, acc_on_device
  use gen_mod
  implicit none
  integer, parameter :: n = 64
  integer, allocatable, target :: a(:), b(:)
  integer :: ref(n)
  integer :: i, host_flag
  logical :: ok
  allocate(a(n), b(n))
  do i = 1, n
    a(i) = i
    b(i) = 0
    ref(i) = 2*i + 1
  end do
  host_flag = 1
  do i = 1, n
    lv(i) = 2*i + 1
  end do
  !$acc parallel loop copyin(a) copyout(b) copy(host_flag) copyin(lv)
  do i = 1, n
    if (i == 1) host_flag = merge(1, 0, acc_on_device(acc_device_host))
    b(i) = get_lv(a(i))
  end do
  ok = all(b == ref)
  print '(a,i0,a,a)', 'RESULT ran_on_host=', host_flag, ' check=', merge('pass', 'fail', ok)
  deallocate(a, b)
end program gen_prog