RAWToJ400 and RGBToJ400 use 2 step row function for Intel. RAWToJ400 Was 3996 ms, now 3309.  20.7% faster.

Call a row function for each row, based on ARGBToI400 code.
But implement row functions as 2 step conversion.  Adds the
row functions:
RAWToYJ, RGBToYJ, SSSE3 and AVX2 versions, and Any versions.
The smaller row buffer is more cache friendly on large images.

The max cache size can be configured, and is currently:
// Maximum temporary width for wrappers to process at a time, in pixels.
And the row buffer is
  SIMD_ALIGNED(uint8_t row[MAXTWIDTH * 4]);
So 8192 bytes are used for the row buffer, leaving the rest for source
and destination buffers.

blaze-bin/third_party/libyuv/libyuv_test '--gunit_filter=*R*To?400_Opt' --libyuv_width=3600 --libyuv_height=2500 --libyuv_repeat=1000 --libyuv_flags=-1 --libyuv_cpu_info=-1 | sortms

Was
RAWToJ400_Opt (3996 ms)
ARGBToI400_Opt (3964 ms)
RGB24ToJ400_Opt (3960 ms)
ARGBToJ400_Opt (3909 ms)
RGBAToJ400_Opt (3885 ms)

Now
ARGBToJ400_Opt (4091 ms)
ARGBToI400_Opt (3936 ms)
RGBAToJ400_Opt (3428 ms)
RGB24ToJ400_Opt (3324 ms)
RAWToJ400_Opt (3309 ms)

Bug: libyuv:854, b/147753855
Change-Id: Ieb65fbda94e812c737f4c3c74107354b73c4bcd2
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/2016203Reviewed-by: richard winterton <rrwinterton@gmail.com>
Commit-Queue: Frank Barchard <fbarchard@chromium.org>