regtest: split reference files allowing tests to run individually

[ffmpeg] / tests / ref / vsynth2 / rc

b517389e425d3065ab26ef4cc0658237 *./tests/data/a-mpeg4-rc.avi
227762 ./tests/data/a-mpeg4-rc.avi
cc947bbac9187bf08d3e2d425556aaa5 *./tests/data/rc.vsynth2.out.yuv
stddev:    4.26 PSNR: 35.54 bytes:  7603200/  7603200