[Bug libgomp/69183] ICE when using OpenMP PRIVATE keyword in OMP DO loop not explicitly encapsulated in OMP PARALLEL region

[gerhard.steinmetz.fortran@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69183

--- Comment #4 from Gerhard Steinmetz <gerhard.steinmetz.fortran@t-online.de> ---
Related (modified example from testsuite) :


$ cat z3.f90
subroutine gang (a)
  !$acc routine gang
  integer, intent(inout) :: a(n)
  integer, allocatable :: i
  !$acc loop
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
  !$acc loop gang
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
  !$acc loop worker
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
  !$acc loop vector
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
end
subroutine worker (a)
  !$acc routine worker
  integer, intent(inout) :: a(n)
  integer, allocatable :: i
  !$acc loop
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
  !$acc loop worker
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
  !$acc loop vector
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
end
subroutine vector (a)
  !$acc routine vector
  integer, intent(inout) :: a(n)
  integer, allocatable :: i
  !$acc loop
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
  !$acc loop vector
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
end
subroutine seq (a)
  !$acc routine seq
  integer, intent(inout) :: a(n)
  integer, allocatable :: i
  !$acc loop
  do i = 1, 2
     a(i) = a(i) - a(i)
  end do
end


$ gfortran-7-20161113 -fopenacc -c z3.f90
z3.f90:5:0:

   !$acc loop

internal compiler error: in build_outer_var_ref, at omp-low.c:1361
0xb27aa2 build_outer_var_ref
        ../../gcc/omp-low.c:1361
0xb41f7a lower_rec_input_clauses
        ../../gcc/omp-low.c:4947
0xb486e9 lower_omp_for
        ../../gcc/omp-low.c:15196
0xb38856 lower_omp_1
        ../../gcc/omp-low.c:17106
0xb38856 lower_omp
        ../../gcc/omp-low.c:17243
0xb3838c lower_omp_1
        ../../gcc/omp-low.c:17091
0xb3838c lower_omp
        ../../gcc/omp-low.c:17243
0xb379ec lower_omp_1
        ../../gcc/omp-low.c:17082
0xb379ec lower_omp
        ../../gcc/omp-low.c:17243
0xb3838c lower_omp_1
        ../../gcc/omp-low.c:17091
0xb3838c lower_omp
        ../../gcc/omp-low.c:17243
0xb3f56f execute_lower_omp
        ../../gcc/omp-low.c:17978
0xb3f56f execute
        ../../gcc/omp-low.c:18015