[CI] Enable building StableHLO in CI

[penguin-wwy]

Context: Due to the LLVM version upgrade, stablehlo CI tests have been temporarily disabled.
Ref link of discussion: #4152

Content of the current PR: The stablehlo version has been updated, but there are still compilation issues. The main reason is that stablehlo’s LLVM cannot be updated to the latest version for now, so it cannot stay in sync with torch-mlir. Therefore, I have added a patch file to fix some API differences. This does not affect functionality. The patch is temporary and is intended to help restore CI testing for the stablehlo backend as soon as possible.

[marbre]

What about patching StableHLO instead of applying a patch as part of the build?

[penguin-wwy]

What about patching StableHLO instead of applying a patch as part of the build?

Upstream is currently unable to update the dependent LLVM to the latest version due to some blocking issues openxla/stablehlo#2788. This results in version differences between the LLVM used by upstream and the one we are using, which leads to compilation problems.

[vivekkhandelwal1]

Hi, I'm not sure if this is the right approach to fix this issue. I have never seen any such patch before where we're directly modifying an external repo inside the project. If the issue is not fixed upstream, then why not wait for some more time?

[marbre]

Hi, I'm not sure if this is the right approach to fix this issue. I have never seen any such patch before where we're directly modifying an external repo inside the project. If the issue is not fixed upstream, then why not wait for some more time?

I strongly agree as this adds an additional maintenance burden to torch-mlir. Is there any strong reason why this cannot be added to StableHLO upstream?

[penguin-wwy]

This patch file can be removed after the two upstream PRs are merged
openxla/stablehlo#2798
openxla/stablehlo#2797

[vivekkhandelwal1]

This patch file can be removed after the two upstream PRs are merged openxla/stablehlo#2798 openxla/stablehlo#2797

Let's wait for those upstream PRs to be merged and then directly do a bump instead of modifying an external repo.