Hi all,

An arm-none-eabi build with RTL checking and --with-cpu=cortex-a9 fails because
cortex_a9_sched_adjust_cost tries to access the SET_DEST of a PARALLEL.
The correct thing to do is to call single_set on dep, which will return a simple SET
that we can take the SET_DEST of or NULL if there's more than one SET.

This patch does that.
The arm-none-eabi build passes.
Bootstrapped and tested on arm-none-linux-gnueabihf.

Ok for trunk?

Thanks,
Kyrill

2015-10-29  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

     * config/arm/arm.c (cortex_a9_sched_adjust_cost): Use reg_set_p to
     check for dependencies.