[Bug fortran/126895] New: Wrong IS_CONTIGUOUS result for pointer assumed-rank scalar values

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126895

            Bug ID: 126895
           Summary: Wrong IS_CONTIGUOUS result for pointer assumed-rank
                    scalar values
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mikael at gcc dot gnu.org
  Target Milestone: ---

IS_CONTIGUOUS returns a wrong value if its argument is a pointer assumed-rank
dummy associated with a scalar value.  The function should always return True
in that case.

From F2023, 16.9.115 IS_CONTIGUOUS(ARRAY):
    The result has the value true if ARRAY has rank zero or is contiguous, and
    false otherwise.

Testcase:

program prog
  implicit none
  type :: t
    integer :: c1
  end type
  type, extends(t) :: u
    integer :: c2
  end type
  type(t), target :: x
  type(u), target :: y
  call s1(x, 1)
  call s1(y, 2)
contains
  subroutine s1(a, e)
    class(t), pointer, intent(in) :: a(..)
    integer, value :: e
    print *, is_contiguous(a)
    !if (.not. is_contiguous(a)) error stop e
  end subroutine
end program

The testcase gives at runtime:
  F
  F

The expected output is:
  T
  T