[flang][OpenMP] Fix mapping of constant arrays. (#176763)

The compiler skips mapping of named constants (parameters) to OpenMP
target regions under the assumption that constants don't need to be
mapped. This assumption is not valid when array is accessed inside with
dynamic index. The problem can be seen with the following code:

```
module fir_lowering_check
  implicit none

    integer, parameter :: dp = selected_real_kind(15, 307)
    real(dp), parameter :: arrays(2) = (/ 0.0, 0.0 /)

contains

subroutine test(hold)

        integer, intent(in) :: hold
        integer :: z
        real(dp) :: temp

        !$omp target teams distribute parallel do
            do z = 1, 2
                  temp = arrays(hold)
            end do
        !$omp end target teams distribute parallel do

    end subroutine test
end module fir_lowering_check

program main
  use fir_lowering_check

  implicit none
    integer :: hold
    hold = 1
    call test(hold)
    print *, "Finished"

end program main
```

It fails with the following error
`'hlfir.designate' op using value defined outside the region`

The fix is to allow mapping of constant arrays and map them as `to`.

0 files changed, 0 insertions, 0 deletions