Matthew Pickering authored Jun 01, 2021 and Marge Bot committed Jun 02, 2021

When compiling Agda we entered into an infinite loop as the stopping
condition was a bit wrong in hptSomeModulesBelow.

The bad situation was something like

* We would see module A (NotBoot) and follow it dependencies
* Later on we would encounter A (Boot) and follow it's dependencies,
  because the lookup would not match A (NotBoot) and A (IsBoot)
* Somewhere in A (Boot)s dependencies, A (Boot) would appear again and
  lead us into an infinite loop.

Now the state marks whether we have been both variants (IsBoot and
NotBoot) so we don't follow dependencies for A (Boot) many times.