swift

250fd3f3 - [AutoDiff] Emit SIL diff witnesses into original function's IRGenModule. (#28237)

[AutoDiff] Emit SIL diff witnesses into original function's IRGenModule. (#28237) The differentiation transform does not yet canonicalize differentiability witnesses so that they always have JVP/VJP functions. TF-894 tracks this. Until then, emit SIL differentiability witness into the IRGenModule for the original function. The significance of this is unclear; `IRGenerator::getGenModule` seems relevant only for multi-threaded compilation. Resolves TF-960: crash when `SILDifferentiabilityWitness::getVJP` is null.