An enumeration of reasons why a chunk might be invalidated.
The chunk is being invalidated because a method it depends on has changed.
The chunk is being invalidated due to it being evicted due to too many chunks being in existence.
The chunk is being invalidated to collect code coverage stats.
The number of invocations that must happen after this invalidation before the code will be optimized into another chunk.
Statistic for tracking the cost of invalidating chunks due to this reason.