AFAIR this is just the beginning of the feature.
This is about having the RTTI for IInvokable interfaces.
At the same level than Delphi 6 - we are not speaking of the Delphi "enhanced RTTI" available since Delphi 2010.
It is not merged to the trunk yet.
We asked for it again last week.
And it would eventually be merged.
Then you would need an "Invoke" feature.
We developed our on "Invoke" stubs for x86 and x64, in our Open Source
https://github.com/synopse/mORMot/blob/master/SQLite3/mORMot.pasYou may use it as a start point.