[Bug fortran/78092] New: ICE when calling SIZEOF on CLASS(*) entry

["holysword at inbox dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78092

            Bug ID: 78092
           Summary: ICE when calling SIZEOF on CLASS(*) entry
           Product: gcc
           Version: 6.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: holysword at inbox dot com
  Target Milestone: ---

The following test program returns an ICE at line 14 for all versions of
gfortran I have tested (up to 6.1)

PROGRAM test_stuff
  IMPLICIT NONE
  INTEGER :: ivar1(2,3), ivar2

  ivar1 = 6
  CALL poly_sizeof(ivar1, ivar2)
  PRINT*, 'ivar2: ', ivar2

  CONTAINS

  SUBROUTINE poly_sizeof(arg1,arg2)
    CLASS(*), INTENT(IN) :: arg1(:,:)
    INTEGER, INTENT(OUT) :: arg2
    arg2 = SIZEOF(arg1(1,1))
  END SUBROUTINE
END PROGRAM test_stuff

Changing the type of arg1 in line 12 to INTEGER compiles the program and gives
the expected result. Changing line 14 to "SIZEOF(arg1)" also works. The problem
seems to be specific for when you require the size of a single element of an
array of unlimited polymorphic variables.