[llvm-branch-commits] [llvm] release/22.x: [arm64ec] Fix missing sret return in Arm64EC entry thunks for large struct returns (#185452) (PR #185967)

[Eli Friedman via llvm-branch-commits]

https://github.com/efriedma-quic approved this pull request.

This is not a regression, but it fixes a significant miscompile.  The codepath in question is only used for Arm64EC.

https://github.com/llvm/llvm-project/pull/185967