Implementing OpenACC's Fortran module

[Tobias Burnus]

Hi James,

James Norris wrote:
> Attached are my latest versions of the OpenACC header files. The testing I've
> done with the headers are using a version of the fortran compiler with your
> patches applied. So far, no issues with the patches!

The patches look good to me, except that I think the TODOs can be removed as
the items has been implemented.

Additionally, I wonder whether one can get rid of the *_h functions and
of making *_l PRIVATE. In particular, I am thinking of replacing in
"module openacc":
  function acc_get_num_devices (d)
by
  function acc_get_num_devices (d) &
      bind(C, name="__openacc_MOD_acc_get_num_device")

And then using those functions in the module instead of the _h functions.

Tobias