I'm filing it here in lack of a better place so that I don't forget about it.

E.g. if a frame couldn't be inlined because it hit MaxInlineDepth, that info could be somehow annotated graphically in the flame graph. Similar for other inlining decisions.

The tool needed would take the output of -XX:+LogCompilation to produce annotations. Flamegraph would need to be able to merge those annotations into the flamegraph.