llvm-project

5d4c4411 - [rtsan] Handle attributed IR function declarations (#169577)

[rtsan] Handle attributed IR function declarations (#169577) Addresses https://github.com/llvm/llvm-project/issues/169377. Previously, the RealtimeSanitizer pass only handled attributed function _definitions_ in IR, and we have recently found that attributed function _declarations_ caused it to crash. To fix the issue, we must check whether the IR function is empty before attempting to do any manipulation of its instructions. This PR: - Adds checks for whether IR `Function`s are `empty()` ~~in each relevant~~ at the top-level RTSan pass routine - ~~Removes the utility function `rtsanPreservedCFGAnalyses` from the pass, whose result was unused and which would otherwise have complicated the fix~~