Update lz4 to v1.8.3
Update lz4 to v1.8.3

This update fixes a data corruption bug. This is a rare bug that only
occurs with a data block > 64KiB. The UnTech compiler is unaffected as
all data blocks are < 64 KiB.

undisbeliever/untech-editor,undisbeliever/untech-editor