* cse.c: Include hashtab.h instead of splay-tree.h
        (struct cse_reg_info): No longer use variant union.  Add new
        field "regno".  All references changed to avoid union.
        (cse_reg_info_used_list, cse_reg_info_used_list_end): New variables.
        (free_cse_reg_info): Remove.
        (hash_cse_reg_info, cse_reg_info_equal_p): New functions.
        (get_cse_reg_info): Revamp to use expandable hash tables instead
        of splay trees.  Initialize new fields in cse_reg_info structure.
        (new_basic_block): Similarly.

From-SVN: r30014