[clang] [LifetimeSafety] Trace assignment history for use-after-scope errors (PR #188467)

[Yuan Suo via cfe-commits]

suoyuan666 wrote:

I've applied the new error format as suggested, but please note that this commit doesn't yet integrate the search logic into other error scenarios—I'll handle that in the next update.

Also, I'm a bit concerned about my current implementation. The filtering process for Expr feels quite redundant and heavy (`GetPureSrcExpr` in AssignmentQuery.cpp). I’m wondering if there are existing utility functions that could simplify this.

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Apologies, due to some improper local operations, I have accidentally squashed multiple commits into this single submission.

https://github.com/llvm/llvm-project/pull/188467