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

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/arsenm/dag/use-poison-getLoad-getStore-offsets'.
Changed from 8f4b3576226743509485afff3baaa63cb20969fa to 7c20e1d885cda69097cc8c9374889a865c599d78
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 7c20e1d885cda69097cc8c9374889a865c599d78 by Matt Arsenault on 29/07/2026 at 09:55..
DAG: Use poison in getLoad/getStore for offsets

The painful part of this is due to a few unfortunate things.

1. poison is legalized to undef
2. Non-indexed load/store encode the offset as an undef (which is
   not like a TargetConstant, and does get legalized)
3. 2 asserts in DAGCombiner expect identical load/store nodes,
   which assumes the offset will be preserved and not converted
   between poison and undef
4. The getLoad/getStore overloads are a mess, and a path was missing
   to recreate the store case with the original offset.
https://invent.kde.org/qt/clang/llvm/-/commit/7c20e1d885cda69097cc8c9374889a865c599d78