The epoll emulation uses data structures without packing them, so the
compiler might choose to add padding inside.

This patch makes the most offending one (target_epoll_event) a packed
structure to make sure we don't pad it by accident. ARM would pad it,
so declare the padding mandatory for ARM targets.

This fixes i386-on-ARM epoll emulation for me.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>