[llvm] [WPD]: Enable speculative devirtualizatoin. (PR #159048)

[Teresa Johnson via llvm-commits]

https://github.com/teresajohnson commented:

Did the building of the ExportSummary get inadvertently removed from this PR? BTW, if you could please avoid force pushing when you update that would make reviewing much easier - as it is I am unable to compare to old versions. See https://llvm.org/docs/GitHub.html#rebasing-pull-requests-and-force-pushes.

https://github.com/llvm/llvm-project/pull/159048