[clang] [llvm] Enable WPD without lto (PR #141777)

[Teresa Johnson via llvm-commits]

teresajohnson wrote:

> Hi @teresajohnson what do you think? For the case of PGO, I think we may disable it. I think The speculative devirtualization is useful for cases where we don't have enough information.

Yes I think the spec results are promising. I'd suggest also trying with a large C++ app like Clang itself, compiling a large source file. Feel free to send a full patch for this change, including some lit tests, and guarded appropriately by a flag.

https://github.com/llvm/llvm-project/pull/141777