Fix register packing for structs in d3d9.

Fixes WebGL test misc/shader-with-array-of-structs-uniform

BUG=angle:656

Change-Id: If79a19db4d40bab9110422f7876de32e7f85e506
Reviewed-on: https://chromium-review.googlesource.com/200620
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Nicolas Capens <nicolascapens@chromium.org>
5 files changed