Show number of leaks in --huntrleaks

[encukou]

Feature or enhancement

Currently, -R (--huntrleaks) only displays the reference counts when the test fails. It also uses a generous heuristic, which avoid false positives, but might hide issues.

To get more insight into what's going on, I propose to show the number of leaks instead of the dot, with

• . instead of 0, so leaks stand out
• X instead of 10 or more, to keep the display as a single digit

Additionally, I'd like to separate warmup runs, so you know when to start worrying.

The output would look like this:

beginning 9 repetitions. Showing number of leaks (. for zero, X for 10 or more)
12345:6789
XX.1. ....

meaning the first 2 warmups “leaked” a lot, then one more had a single “leak”, and there were no more leaks.

Linked PRs

• gh-115720: Show number of leaks in huntrleaks progress reports #115726

[encukou]

Merged.
The behaviour is slightly different, to account for negative “leak counts”; for details see af5f9d6. (Or a test run -- the output should be self-descriptive.)

I plan to leave this in main for a while before deciding about backports.