[llvm] [docs] Strengthen our quality standards and connect AI contribution policy to it (PR #154441)

[Reid Kleckner via llvm-commits]

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@@ -424,6 +430,39 @@ squashing and merging PRs.
 For minor violations of these recommendations, the community normally favors
 reminding the contributor of this policy over reverting.
 
+Post-commit responsibilities
+----------------------------
+
+After landing a change, the committer is responsible for addressing any problems
+found in the future that the change is responsible for.  For example:
+
+* The code should compile cleanly on all supported platforms.
+
+* The changes should not cause any correctness regressions in the ``llvm-test``
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rnk wrote:

This was the text as it was written in the previous pre-commit quality bar section, but yes, I interpret it that way, and I'll make that update.

https://github.com/llvm/llvm-project/pull/154441