build on MacOS

[fmaxx]

./build.sh -j 4 -B
..........................
install -m 644 libx264.a /Volumes/SD/1/ffmpeg-static/target/lib
ranlib /Volumes/SD/1/ffmpeg-static/target/lib/libx264.a
*** Building x265 ***
rm: ./CMakeFiles/3.13.4: No such file or directory

MacOS: 10.14.3