Add a test which exercises a wide range of code-paths for imported dmabufs in the iris driver. It has:
- Caught some bugs and motivated bug fixes (mesa!4972 (merged), mesa!6092 (merged), mesa!6095 (merged), mesa!13326 (merged), mesa!14082 (merged)).
- Enabled the reproduction of a bug (mesa#3425 (closed)).
- Motivated making iris a bit more flexible (mesa!6296 (merged)).
- Helped the development of MC_CCS for iris (mesa!6449 (merged)).
- Helped the development of RC_CCS_CC for iris (mesa!9230 (merged)).
It has support for loading dmabufs from binaries, but the binaries and the function implementation needed to enable this are not included. For an example of how to use this feature, see this branch.