* basic-block.h: Give the BB flags enum a name, bb_flags.
Add new flags BB_FORWARDER_BLOCK, and BB_NONTHREADABLE_BLOCK.
* cfgcleanup.c (enum bb_flags): Remove here.
(BB_FLAGS, BB_SET_FLAG, BB_CLEAR_FLAG): Remove.
(notice_new_block): Set/test bb->flags instead of aux via BB_FLAGS.
(update_forwarder_flag): Likewise.
(thread_jump): Likewise.
(try_forward_edges): Likewise.
(try_optimize_cfg): Likewise. Clear bb->flags before updating the
forwarder flags. Don't clear bb->aux for all basic blocks. Only
reset the BB_FORWARDER_BLOCK and BB_NONTHREADABLE_BLOCK flags.
From-SVN: r101876
