Modified copy of zlib from https://github.com/brianhelba/zipfile-deflate64
(at https://github.com/cielavenir/zlib_infback9_resumable/tree/beaec8dc39f5caa86e808611b10f2ea0ab8720c2)

zipfile-deflate64 modified copy has logic to save & restore
state at beginning and end of inflateBack9(), to allow incremental decoding.

GDAL's changes are regarding the "left" and "put" variables

GDAL also adds a inflateBack9Copy() to allow snapshoting of decompression
state.
