[flang][debug] Support assumed shape arrays. (#94644)

This PR generates dwarf to extract the information about the arrays from
descriptor. The DWARF needs the offset of the fields like `lower_bound`
and `extent`. The getComponentOffset has been added to calculate
them which pushes the issue of host and target data size into
getDescFieldTypeModel.

As we use data layout now, some tests needed to be adjusted to have a
dummy data layout to avoid failure.

With this change in place, GDB is able show the assumed shape arrays
correctly.

  subroutine ff(n, m, arr)
    integer n, m
    integer :: arr(:, :)
    print *, arr
    do i = 1, n
      do j = 1, m
        arr(j, i) = (i * 5) + j + 10
      end do
    end do
    print *, arr
  end subroutine ff

Breakpoint 1, ff (n=4, m=3, arr=...) at test1.f90:13
13          print *, arr
(gdb) p arr
$1 = ((6, 7, 8, 9) (11, 12, 13, 14) (16, 17, 18, 19))
(gdb) ptype arr
type = integer (4,3)
(gdb) c
Continuing.
 6 7 8 9 11 12 13 14 16 17 18 19