This patch permits

   interface
      subroutine sub (x)
         real x(10)[*]
      end subroutine
   end interface
   real :: x(100)[*]
   call sub (x(10))
   end

where one passes an array element ("x(10)") of a contiguous array to a
coarray dummy argument. That's permitted per interpretation request
F08/0048, which ended up in Fortran 2008's Corrigendum 2 - and is also
in the current Fortran 2015 drafts:

"If the dummy argument is an array coarray that has the CONTIGUOUS attribute
 or is not of assumed shape, the corresponding actual argument shall be
 simply contiguous or an element of a simply contiguous array."

the "or ..." of the last line was added in the corrigendum.


I hope and think that I got the true/false of the other users correct - in
most cases, it probably doesn't matter as the caller is only reached for
expr->rank > 0.

Build and regtested on x86-64-gnu-linux.
OK for the trunk?

Tobias