[clang] [HLSL][DirectX] Add the Qdx-rootsignature-strip driver option (PR #154454)

[Chris B via cfe-commits]

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@@ -4647,6 +4647,16 @@ void Driver::BuildDefaultActions(Compilation &C, DerivedArgList &Args,
     // Only add action when needValidation.
     const auto &TC =
         static_cast<const toolchains::HLSLToolChain &>(C.getDefaultToolChain());
+    if (TC.requiresObjcopy(Args)) {
+      Action *LastAction = Actions.back();
+      // llvm-objcopy expects a DXIL container, which can either be
+      // validated (in which case they are TY_DX_CONTAINER), or unvalidated
+      // (TY_OBJECT).
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llvm-beanz wrote:

Didn't we confirm this should only run on unvalidated containers?

https://github.com/llvm/llvm-project/pull/154454