[Bug fortran/64943] New: No error on ultimate allocatable components in IO list

["pault at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64943

            Bug ID: 64943
           Summary: No error on ultimate allocatable components in IO list
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pault at gcc dot gnu.org

With this wrong code (other brand: Variables containing ultimate allocatable
array components are forbidden from appearing directly in input/output lists.
print *, TestReference([Test(99), Test(199)])):

  type :: Test
    integer :: i
  end type

  type :: TestReference
     class(Test), allocatable :: test(:)
  end type
print *, TestReference([Test(99), Test(199)])
end

5.0 gives:

f951: internal compiler error: Bad IO basetype (7)
0x62a1fb gfc_internal_error(char const*, ...)
    ../../trunk/gcc/fortran/error.c:1486
0x71738b transfer_expr
    ../../trunk/gcc/fortran/trans-io.c:2265
0x71724a transfer_expr
    ../../trunk/gcc/fortran/trans-io.c:2259
0x71ad25 gfc_trans_transfer(gfc_code*)
    ../../trunk/gcc/fortran/trans-io.c:2395
0x6ba7e7 trans_code
    ../../trunk/gcc/fortran/trans.c:1853
0x718790 build_dt
    ../../trunk/gcc/fortran/trans-io.c:1921
0x6ba807 trans_code
    ../../trunk/gcc/fortran/trans.c:1825
0x6e6008 gfc_generate_function_code(gfc_namespace*)
    ../../trunk/gcc/fortran/trans-decl.c:5842
0x6778c0 translate_all_program_units
    ../../trunk/gcc/fortran/parse.c:5341
0x6778c0 gfc_parse_file()
    ../../trunk/gcc/fortran/parse.c:5538
0x6b7675 gfc_be_parse_file
    ../../trunk/gcc/fortran/f95-lang.c:228