[MFMA][Test] Add scripts generating mfma related lit tests

[binarman]

This PR adds scripts for lit test generation.

[zhanglx13]

@binarman
I can see the value of auto test generator, especially for mfma instructions today and in the future. However, this script is just a one time thing unless you can integrate it into some cmake system so that such tests can be generated automatically when people do pip install triton for the first time. We can leave such work as triton onboard task. I don't expect to spend your time in this.
So since you already have the tests generated, should we close this PR?

[binarman]

I agree that it would be good to integrate this script in cmake, but I did not update it too frequently, so I did not bother do an integration.

However I can not agree that this is one time thing, I've used this script to generate tests at least 3 times to this date(and regenerate them during debugging few more times):

• initial generation
• changes in syntax of mfma layout after: [MFMA] Cleanup mfma pipeline #479
• for second version of mfma 4x64 layout, that I am working at the moment: [MFMA] MFMA 4x64 64x4 version 2 #539

[zhanglx13]

By "one time" I mean after the tests are generated, they live with the repo. And when people git clone our fork, they will have the tests and do not need to run the test-gen script to generate the tests again.
I can see you need to tweak it along the time. And you probably will in the future. I'll let you decide if you want to keep this PR.

[alefimov-amd]

I would like to merge this in triton-mlir.
I was thinking about reimplementing these tests (at least some of them) in gtest, so test and "ir generator" will be the same thing. But it requires some time so I think I'll do this in upstream.