This item was fixed in a different way, so has been removed:

<
< * Allow free-behind capability for large sequential scans to avoid
<   kernel cache spoiling
<
<   Posix_fadvise() can control both sequential/random file caching and
<   free-behind behavior, but it is unclear how the setting affects other
<   backends that also have the file open, and the feature is not supported
<   on all operating systems.