Tracking issue for https://github.com/golang/go/issues/47725

[scott-cotton]

golang/go#47725 highlights some problems with the serialisation and filtering mechanism of Facts in go's analysis library.

This issue is here to track how pal interacts with it.

At this time, pal has only been tested as a single/multi checker, and we have tried to work around the whole fact mechanism as it does not seem to fit pal's needs.