Revert "Update opcodes.h thx to Arctium"

This reverts commit 72c3dc3b020b7d1ecfbdbb8c001bc18b8d776bf9.
Revert "Part 1 Update to 5.4.1 (17538)"

This reverts commit 197b1feea26bd8365bc9cd633379b1996a153d83.
update readme