Artifacts with multiple QQuickViews and Intel GPUs on linux

Summary of the findings:
1. See picture (not video) below for the effect.
2. You need ArchLinux with intel 3000 graphics to reproduce it, or at least both reporters (Jocelyn Turcotte and Oleg Shparber) have such a setup.
3. Apparently it is only triggered if you have multiple QQuickViews next to each other, as the QML profiler did before the workaround/fix. They have to be in window containers; it doesn't happen if you use QQuickWidget.
4. It seems the fact that all of those views use Canvas items has something to do with it.
5. This is with single-threaded rendering. It seems using multi-threaded rendering works around the issue in some cases (if you ignore the frequent crashes caused by buggy drivers).