OpenBSD 5.4 to prevent picking up ports libreadline if installed during
build, but this was fixed differently in the libreadline port after 5.5
instead (by moving the headers to a directory which is not usually
picked up by default).
Found while investigating why readline is broken in the Python 3.10
port (but doesn't fix that issue). Also changes to the build in py3.10
mean that this patching no longer worked for the original issue.
ok kmos@
bf5b2cd548