This change was necessary for my upcoming changes to introduce side effect instructions for indirections of smart pointers. The code to decide which parameters have which side effects appeared in both the IPA constructor for `TTranslatedSideEffect` and in `TranslatedCall`. These two versions didn't quite agree, especially once the `SideEffectFunction` model provides its own side effects instead of the defaults.
The relevant code has now been factored out into `SideEffects.qll`. This queries the model if one exists, and provides default side effects if no model exists. This fixes at least one existing issue, where we were emitting a buffer read side effect for `*this` instead of an indirect read side effect. This accounts for all of the IR diffs in the tests.
Eliminates _almost_ all of the bespoke type trackers found here. The
ones that remain do not fit easily inside the framework of API graphs
(at least, not yet), and I did not see any easy ways to clean them up.
They have, however, been rewritten to use `LocalSourceNode` internally,
which was the primary goal of this exercise.
I'm sure we could also clean up many of the inner modules given the more
lean presentation we have now, but this can wait for a different PR.
Because the replacement extension point now extends `API::Node`, I
modified the `toString` method of the latter to have an empty body.
The alternative would be to require everyone to provide a `toString`
predicate for their extensions, but seeing as these will usually be
pointing to already existing API graph nodes, this seems silly.
(This may be the reason why the equivalent method in the JS libs has
such an implementation.)
We were missing out on `None`, `True`, and `False` as these do not
appear as actual attributes of the `builtins` module in Python 3
(because they are elevated to the status of keywords there)
The simple solution, then, is to just always include them directly.
