Per https://lists.llvm.org/pipermail/llvm-dev/2021-August/152305.html.
Reviewed By: MaskRay, fhahn
Differential Revision: https://reviews.llvm.org/D109080
Changes to the LLVM IR
----------------------
-* ...
+* Using the legacy pass manager for the optimization pipeline is deprecated and
+ will be removed after LLVM 14. In the meantime, only minimal effort will be
+ made to maintain the legacy pass manager for the optimization pipeline.
Changes to building LLVM
------------------------