backport: re PR rtl-optimization/48144 (ICE: in code_motion_path_driver, at sel-sched...

backport: re PR rtl-optimization/48144 (ICE: in code_motion_path_driver, at sel-sched.c:6575 with -fselective-scheduling2 and custom flags)

        Backport from mainline
        2011-03-26  Andrey Belevantsev  <abel@ispras.ru>

        PR rtl-optimization/48144
        * sel-sched-ir.c (merge_history_vect): Factor out from ...
        (merge_expr_data): ... here.
        (av_set_intersect): Rename to av_set_code_motion_filter.
        Update all callers.  Call merge_history_vect when an expression
        is found in both sets.
        * sel-sched-ir.h (av_set_code_motion_filter): Add prototype.

From-SVN: r172089