[clang] [Clang][Driver] Accept `--offload-jobs` without parallel work (PR #214310)

[Yaxun Liu via cfe-commits]

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@@ -5610,6 +5605,7 @@ void Driver::BuildJobs(Compilation &C) const {
       J.InProcess = false;
 
   markOffloadDeviceCC1JobsForParallelExecution(C);
+  claimAndDiagnoseOffloadJobs(*this, C.getArgs());
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yxsamliu wrote:

Agreed. I will only claim `--offload-jobs` when offloading is active. A normal C++ compilation will still report it as unused. CMake can test the option using a HIP/offload compilation.

https://github.com/llvm/llvm-project/pull/214310