Log Message:
Update to 6.9. From the changelog:

- This is oksh-6.9, matching ksh(1) from OpenBSD 6.9 with portability
  additions.

From the OpenBSD 6.9 changelog:

- Fixed ksh(1) redrawing of a multiline PS1 prompt in vi mode and added
  support for ^R (redraw) in insert mode.