llvm-project

f00ec3f7 - [NFC][LifetimeSafety]: Track assignment history within a single CFGBlock (#196075)

[NFC][LifetimeSafety]: Track assignment history within a single CFGBlock (#196075) ## Summary Tracking assignment history allows us to backtrack and provide more informative error messages, helping users better understand the root cause. As discussed in https://github.com/llvm/llvm-project/pull/188467#issuecomment-4359071778, I am splitting the original #188467 into smaller parts. This PR submits the core logic: performing a reverse search for assignment history within a single CFG block. A simple unit test has been added to verify the basic functionality of the algorithm. ## Details This function is straightforward: it iterates through each `OriginFlowFact` in reverse order and saves the appropriate `SrcOriginID`. Here, "appropriate" means the `Origin` contains the target `Loan`. --------- Signed-off-by: Yuan Suo <suoyuan666@s5n.xyz>