Feature: Instant Events

[amcasey]

It might be interesting to report the stacks in which instant events (esp depth limits) occur (hot stacks only?), but we'd need to find a readable output format.

[amcasey]

Anecdotally, files with lots of instant events tend to contain complex types but are not directly correlated with perf issues (presumably because they bailed and triggered an instant event before they got expensive).