As part of incremental compilation performance improvements, we need
to track the dependencies of files due to expressions being evaluated by
the `PartialEvaluator`.
The `PartialEvaluator` now accepts a `DependencyTracker` object, which is
used to track which files are visited when evaluating an expression.
The interpreter computes this `originatingFile` and stores it in the evaluation
`Context` so it can pass this to the `DependencyTracker.
The `IncrementalState` object implements this interface, which allows it to be
passed to the `PartialEvaluator` and so capture the file dependencies.
PR Close#30238