[llvm] [NFC][AMDGPU] Do not flush after printing every instruction (PR #95237)

[Pierre van Houtryve via llvm-commits]

Pierre-vh wrote:

> I don't see how this resolves the problem. Given two streams are getting flushed interleaved at random points, it's not even guaranteed that the combined output contains complete lines. Also not going to work where check lines match both stdout and stderr and thus expect them to come in a particular order.

It resolves the problem because checking stderr/stdout being interleaved isn't a particularly good idea, IMO. With that pattern you only need to check stderr.

> You can redirect stderr to a temp file and then just have another FileCheck run

I think this is the right way to do it, yes.
I also don't see why a test checking decoding failures should be checking decoding success. It seems like the test should be split in half

Though, I'm intrigued by the possibility that stdout/stderr could overlap in the output, like in the terminal. I'd need to see a real example of it happening though before I do any changes in that direction

https://github.com/llvm/llvm-project/pull/95237