[MLIR][NFC] Mark barrier elimination helper static

[sommerlukas]

Make local helper functions static to avoid symbol name collision.

[joker-eph]

Please do not use the "subscribers" teams as a "request review" facility. They aren't named "reviewer" intentionally

[sommerlukas]

Please do not use the "subscribers" teams as a "request review" facility. They aren't named "reviewer" intentionally

I did not specify the reviewers at all, when creating the PR through the web-interface, it did not let me specify reviewers. I think the team was requested automatically, sorry for that. Maybe the setup can be improved?

[joker-eph]

OK: if you didn't specify it, it means that this how the tooling it setup, I didn't expect it would be done this way (especially since we have overlapping teams for codepaths), thanks for letting me know!

[ftynse]

The "codeowners"-based tooling assigns the codeowner group if any of the owned files are touched. I think for issues we have a bot that posts a comment tagging the relevant group, which also sends an email/notification. This sounds preferable to pretending any subscriber is a code owner.