Provide visualizations of executor graphs

[markshannon]

Feature or enhancement

Proposal:

Visualizations can help us understand what is going on with executors. How they link to each other, where they drop to tier 1, etc, etc.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• GH-126833: Dumps graphviz representation of executor graph. #126880

[markshannon]

Here's a quick hacked up visualization of the executor graph after running the infamous pystones "benchmark".
It includes:

• function names and line numbers of ENTER_EXECUTOR,
• arrows attached to instructions, rather than exits
• execution counts

@brandtbucher Is this good enough to start with?