psyir support for arrays declared with indexed bounds

[rupertford]

We need to add support for arrays declared like a(0:n-1). At the moment they are stored as unknown fortran type, however this caused psyad to fail in poly2d_w3_reconstruction_kernel_mod.F90

[arporter]

This is also an issue in WW3 code - it prevents the application of HoistLocalArrayTrans to quite a number of arrays.

[arporter]

It is also an issue in NEMO 4.2 now that the tiling complicates the array declarations.

[arporter]

Simon has reported that when PSyclone processes, e.g.:

subroutine my_sub(arg)
  implicit none
  real, dimension(2:) :: arg
  arg(:) = 0.0
end subroutine my_sub

then it loses the lower bound of the array declaration and generates incorrect code:

subroutine my_sub(arg)
  real, dimension(:) :: arg

  arg(:) = 0.0

end subroutine my_sub

[arporter]

So far it seems that the forms of declaration that this issue was originally opened for are already supported. However, a(4:) ends up with an ArrayType with shape = [Extent.Attribute] which explains why we lose the lower bound.

[arporter]

I think we want shape = [ArrayBounds(Literal(4), Extent.Attribute)]

[arporter]