Atomic init cleanup

Fix a small bug in AtomicInit stringification, by having it derive from OrderedAtomic and using the same __str__ method as other atomics.

Additionally, print the kernel in test_atomic_init to test

added 61 commits

• da269cd6...81fe8355 - 60 commits from branch inducer:master
• 9919af77 - Merge branch 'master' of https://gitlab.tiker.net/inducer/loopy into atomic_init_cleanup

Compare with previous version

enabled an automatic merge when the pipeline for 9919af77 succeeds

Thx!

merged

mentioned in commit be530055