[clang] [llvm] [WPD]: Apply speculative WPD in non-lto mode. (PR #145031)

[Hassnaa Hamdi via llvm-commits]

hassnaaHamdi wrote:

About the failing test, after modifying the Microsoft ABI to allow emitting vtable MD -similarly to what I did for Itanium ABI-, I found out that the GlobalOpt pass can't eliminate the generated unused Vtable aliases because their linkage is `ExternalLinkage` which is explicitly set by the Microsoft ABI.
That is according to the logic at: `MicrosoftCXXABI::getAddrOfVTable(..)`.
So, I think the solution for the failing test is to explicitly add a target to exclude running for windows.
But that seems like devirtulalizaiton will not be enabled for windows!

https://github.com/llvm/llvm-project/pull/145031