[qt/clang/llvm]: Summary of bulk changes made

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/usx95/04-07-field-sensitivity'.
Changed from b516333c9b608616c7e77aa538c68a06163613c0 to f138ded1745f87eb732fa32ece536e1578714d5d
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit 7d3f6dd010abe17832257522605f633689d41842 by Utkarsh Saxena on 24/07/2026 at 21:24..
[LifetimeSafety][NFC] Refactor AccessPath and Loan representations

This patch refactors the internal representations of `AccessPath` and `Loan` to support path elements, preparing for field-sensitive and interior-sensitive lifetime tracking.

- Introduces `PathElement` representing a field or interior dereference.
- Refactors `AccessPath` to contain a base and a list of `PathElement`s.
- Updates `Loan` and `LoanManager` to use the new `AccessPath` structure.
- Refactors debug dump formatting to output path elements if present.
- Updates Checker and FactsGenerator to compile with the new interfaces, keeping logic behaviorally identical (NFC).

TAG=agy
CONV=2cfd8d00-18d7-4a03-8d78-2aba2f9a8f23
https://invent.kde.org/qt/clang/llvm/-/commit/7d3f6dd010abe17832257522605f633689d41842

Git commit 0209269c96d91a1a063541d5e5ff9ef847e4d242 by Utkarsh Saxena on 24/07/2026 at 21:24..
[LifetimeSafety][NFC] Update Checker to use prefix comparison interfaces

This patch switches the Checker's expiry and invalidation checks to use `AccessPath::isPrefixOf` instead of equality (`==`).

Since all generated access paths are currently empty, `isPrefixOf` is behaviorally identical to `==` (NFC). This prepares the checker to handle nested paths (fields and container interiors) in subsequent commits.

TAG=agy
CONV=2cfd8d00-18d7-4a03-8d78-2aba2f9a8f23
https://invent.kde.org/qt/clang/llvm/-/commit/0209269c96d91a1a063541d5e5ff9ef847e4d242

Git commit f138ded1745f87eb732fa32ece536e1578714d5d by Utkarsh Saxena on 24/07/2026 at 21:39..
[LifetimeSafety] Support field-sensitivity in lifetime tracking

This patch enables field-sensitivity when tracking lifetimes of nested objects.

- FactsGenerator now generates `PathElement::getField` for `MemberExpr` accesses, mapping fields to loans.
- LoanPropagation now propagates field paths along flow facts, appending fields to base loans.
- Removes false-positive warnings in `invalidations.cpp` where modifications to one field were incorrectly reported as invalidating iterators/pointers to another field.
- Adds comprehensive unit tests checking nested field access and placeholder fields.

TAG=agy
CONV=2cfd8d00-18d7-4a03-8d78-2aba2f9a8f23
https://invent.kde.org/qt/clang/llvm/-/commit/f138ded1745f87eb732fa32ece536e1578714d5d