These files use the macro OSL_BIGENDIAN but did not include the header
that defines it.

Found via:

git grep -l OSL_.*ENDIAN | grep -E '\.h(xx)?$' | while read f; do grep -L endian\\.h $f ; done

Change-Id: Iffb36336026e49a9c3d8fcf125a54ec857c7552e