[patch] Fix aliasing problem with fortran

[Tobias Schlüter]

Zdenek Dvorak wrote:
> Bootstrapped & regtested on i686.
> 
> Zdenek
> 
> 	* trans-types.c (gfc_array_range_type): New variable.
> 	(gfc_init_types): Initialize gfc_array_range_type.
> 	(gfc_get_array_type_bounds): Use gfc_array_range_type.
> 

Can you also apply this patch to the 4.0 branch please?  It fixes PR 16898 and
the associated testcase gfortran.dg/ret_pointer_1.f90.  Can you then please
close the PR and un-XFAIL the testcase?

Thanks,
- Tobi