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

[Hassnaa Hamdi via cfe-commits]

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@@ -1342,26 +1353,28 @@ bool DevirtModule::trySingleImplDevirt(
   // If the only implementation has local linkage, we must promote to external
   // to make it visible to thin LTO objects. We can only get here during the
   // ThinLTO export phase.
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hassnaaHamdi wrote:

The commented code in this file just means that it's not needed for the case with `nolto`.
But of course if the idea in general got accepted, these code will be refactored to be enabled only with `lto`.

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