[4.5] Find more autoinc addressing for induction variables

[Zdenek Dvorak]

Hi,

> I've tested this on ppc-eabisim, and it does seem to generate preinc
> addressing modes there.  It also survives a regression test on that target.

the patch is OK.

> +  renumber_gimple_stmt_uids_in_blocks (get_loop_body (loop), loop->num_nodes);

The memory allocated by get_loop_body needs to be freed to avoid a
memory leak,

Zdenek