- tx_size: 4x4, 8x8, 16x16.
- tx_type: FLIPADST_DCT, DCT_FLIPADST, FLIPADST_FLIPADST,
  ADST_FLIPADST, FLIPADST_ADST.
- Encoder speed improvement:
  park_joy_1080p_12: ~11%, crowd_run_1080p_12: ~7%.
- Add unit test cases for bit-exact against C.

Change-Id: Ia69d069031fa76c4625e845bfbfe7e6f6ed6e841