re PR middle-end/28071 (A file that can not be compiled in reasonable time/space)

re PR middle-end/28071 (A file that can not be compiled in reasonable time/space)

PR middle-end/28071
* sched-int.h (struct deps): Split field 'pending_lists_length' into
'pending_read_list_length' and 'pending_write_list_length'.  Update
comment.
* sched-deps.c (add_insn_mem_dependence): Change signature.  Update
to handle two length counters instead of one.  Update all uses.
(flush_pending_lists, sched_analyze_1, init_deps): Update to handle
two length counters instead of one.
* sched-rgn.c (propagate_deps): Update to handle two length counters
instead of one.

From-SVN: r123874