As we continue to explore Stencil and revisit the tradeoffs of syntax-parsing JavaScript, it makes sense to have telemetry on the fraction of scripts/functions that are actually delazified.

A simple way to begin this would be to increment a counter in BaseScript::finalize (which is main-thread only) and at the end of the finalize accumulate that into telemetry.

These counters could check for BaseScript::hasBytecode. This basic view will be confused by relazified flags, but we can add a simple MutableFlag that is set on relazification.