[Bug fortran/70853] ICE on pointing to null, in gfc_add_block_to_block, at fortran/trans.c:1599

["gerhard dot steinmetz dot fortran at t-online dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70853

--- Comment #3 from Gerhard Steinmetz <gerhard.steinmetz.fortran@t-online.de> ---
Another testcase :


$ cat z7.f90
program p
   integer, parameter :: m = 2, n = 3
   real, target :: a(m*n)
   real, pointer :: z(:,:) => null()
   z(1:m,1:n) => null()
end


$ gfortran-7-20160821 z7.f90
z7.f90:5:0:

    z(1:m,1:n) => null()

internal compiler error: tree check: did not expect class 'type', have 'type'
(integer_type) in append_to_statement_list, at tree-iterator.c:92
0xead267 tree_not_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
        ../../gcc/tree.c:9842
0xcab3ff non_type_check(tree_node*, char const*, int, char const*)
        ../../gcc/tree.h:3202
0xcab3ff append_to_statement_list(tree_node*, tree_node**)
        ../../gcc/tree-iterator.c:92
0x71f050 add_expr_to_chain
        ../../gcc/fortran/trans.c:1564
0x7213dd gfc_add_expr_to_block(stmtblock_t*, tree_node*)
        ../../gcc/fortran/trans.c:1577
0x7213dd gfc_add_block_to_block(stmtblock_t*, stmtblock_t*)
        ../../gcc/fortran/trans.c:1599
0x768486 gfc_trans_pointer_assignment(gfc_expr*, gfc_expr*)
        ../../gcc/fortran/trans-expr.c:8023
0x71fafa trans_code
        ../../gcc/fortran/trans.c:1695
0x74e708 gfc_generate_function_code(gfc_namespace*)
        ../../gcc/fortran/trans-decl.c:6204
0x6da360 translate_all_program_units
        ../../gcc/fortran/parse.c:5916
0x6da360 gfc_parse_file()
        ../../gcc/fortran/parse.c:6122
0x71c602 gfc_be_parse_file
        ../../gcc/fortran/f95-lang.c:198