Open Unix.LargeFile to avoid "lstat: Value too large for defined data type".

Open Unix.LargeFile to avoid "lstat: Value too large for defined data type".

On 32 bit platforms, because OCaml native ints are limited to 31 bits,
there is a trap in the normal Unix.stat, Unix.lstat functions where
any field in the stat struct may overflow.  The result is random
errors like:

  supermin: error: lstat: Value too large for defined data type: /tmp/tmp.Ss9aYEBASm/d2/root

You would probably only see this on armv7.

The OCaml Unix module has a "LargeFile" submodule which fixes this by
using int64 for some (unfortunately not all) fields.

For more information see the OCaml sources, file
otherlibs/unix/stat.c, all instances of "EOVERFLOW".

Gbp-Pq: Name 0001-Open-Unix.LargeFile-to-avoid-lstat-Value-too-large-f.patch