llvm-project

c05e29bf - [LegacyPM][DirectX] Add legacy scalarizer back for use in the DirectX backend (#107427)

[LegacyPM][DirectX] Add legacy scalarizer back for use in the DirectX backend (#107427) As discussed in this [proposal](https://github.com/llvm/wg-hlsl/pull/62/files?short_path=ac6e592#diff-ac6e59276afe8016e307eedc5c835f534c0cb353707760b44df0fa9d905a5cf8). We had to bring back the legacy pass manager interface for the scalarizer pass. Two reasons for this: 1. The DirectX backend is still using the legacy pass manager 2. The new PM isn't hooked up in clang yet via `BackendUtil.cpp`'s `AddEmitPasses` That means even if we add a `buildCodeGenPipeline` we won't be able to benefit from the new pass manager's scalarizer pass interface. The remaining changes are hooking up the scalarizer pass to the DirectX backend, updating the DirectX test cases, and allowing the `optdriver` to not block the legacy invocation of the scalarizer pass. Future work still needs to be done to allow the scalarizer pass to handle target specific intrinsics. closes #105178