[llvm] [VPlan] Preserve IsSingleScalar for sunken predicated stores. (PR #184329)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon approved this pull request.

LGTM, thanks! Add a "Fixes ..." to the commit message before landing?

https://github.com/llvm/llvm-project/pull/184329