cse.c: (struct cse_basic_block_data): Remove LAST field.

	* cse.c: (struct cse_basic_block_data): Remove LAST field.
	(struct branch_path): Remove BRANCH and TAKEN fields. Add new
	BB field.
	(cse_visited_basic_blocks): New static bitmap.
	(cse_end_of_basic_block, cse_basic_block): Remove.
	(cse_find_path, cse_dump_path, cse_prescan_path,
	cse_extended_basic_block): New static functions.
	(cse_insn): Don't CSE over setjmp calls.  Use the CFG to find
	basic block boundaries.  Don't record jump equivalences here.
	Update the CFG after doing in-place replacement of the SET_SRC.
	(cse_main): Rewrite.  Look for extended basic block headers
	and call cse_extended_basic_block on them until all paths that
	start at this header are exhausted.
	(rest_of_handle_cse): Verify that the CFG is incrementally updated
	and correct after cse_main.
	Don't call delete_trivially_dead_insns, let cfgcleanup do that.
	(rest_of_handle_cse2): Verify the CFG here, too, after cse_main.
	(pass_cse): Add TODO_verify_flow.
	(pass_cse2): Likewise.

From-SVN: r119706