loop-unroll.c (struct iv_to_split): Add pointer to next.

* loop-unroll.c (struct iv_to_split): Add pointer to next.
(struct var_to_expand): Likewise.
(struct opt_info): Add head and tail for linked lists of the above.
(analyze_insn_to_expand_var): Initialize next.
(analyze_iv_to_split_insn): Likewise.
(analyze_insns_in_loop): Create linked lists.
(allocate_basic_variable): Simplify for use without hash table.
(insert_var_expansion_initialization): Likewise, make it type-safer.
(combine_var_copies_in_loop_exit): Likewise.
(apply_opt_in_copies): Walk lists rather than hash tables.
(release_var_copies): Simplified and inlined by hand into...
(free_opt_info): ... this function.

From-SVN: r148090