[clang] [LifetimeSafety] Use buildOriginFlowChain for remaining diagnostics in issuePendingWarnings (PR #212083)

[Yuan Suo via cfe-commits]

suoyuan666 wrote:

I've rebased this PR onto the latest main branch and resolved the merge conflicts. It should be ready to merge now.

By the way, I noticed that there seems to be fewer changes under clang/test than I remembered. I haven't investigated yet whether this is because my implementation is no longer applicable to the current codebase.

https://github.com/llvm/llvm-project/pull/212083