Commits
Merge pull request #2078 in HDFFV/hdf5 from ~NFORTNE2/hdf5_naf:develop to develop * commit '73709ef2fa2494e675566dd3310c6c8ebac01c18': Add H5VL_MAP_OPTIONAL operation id (unused currently).
Merge pull request #2078 in HDFFV/hdf5 from ~NFORTNE2/hdf5_naf:develop to develop * commit '73709ef2fa2494e675566dd3310c6c8ebac01c18': Add H5VL_MAP_OPTIONAL operation id (unused currently).