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

Git repository change summary for qt/clang/llvm-project
Pushed by mirror-service into branch 'upstream/users/usx95/04-07-field-sensitivity'.
Changed from 50f94378216de227962fbb976be413ac6cd5d58f to b516333c9b608616c7e77aa538c68a06163613c0
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 950fb4c6bf64025f572fe2209e9267c00025edf1 by Utkarsh Saxena on 24/07/2026 at 14:22..
[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-project/-/commit/950fb4c6bf64025f572fe2209e9267c00025edf1

Git commit 46931a7684da9f755c0137abd254efadb7b8ce77 by Utkarsh Saxena on 24/07/2026 at 14:22..
[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-project/-/commit/46931a7684da9f755c0137abd254efadb7b8ce77

Git commit b516333c9b608616c7e77aa538c68a06163613c0 by Utkarsh Saxena on 24/07/2026 at 14:25..
[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-project/-/commit/b516333c9b608616c7e77aa538c68a06163613c0