[llvm] [llvm-exegesis] Add support for pinning benchmarking process to a CPU (PR #85168)

[Clement Courbet via llvm-commits]

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@@ -577,11 +612,11 @@ BenchmarkRunner::getRunnableConfiguration(
 Expected<std::unique_ptr<BenchmarkRunner::FunctionExecutor>>
 BenchmarkRunner::createFunctionExecutor(
     object::OwningBinary<object::ObjectFile> ObjectFile,
-    const BenchmarkKey &Key) const {
+    const BenchmarkKey &Key, std::optional<int> BenchmarkProcessCPU) const {
   switch (ExecutionMode) {
   case ExecutionModeE::InProcess: {
     auto InProcessExecutorOrErr = InProcessFunctionExecutorImpl::create(
-        State, std::move(ObjectFile), Scratch.get());
+        State, std::move(ObjectFile), Scratch.get(), BenchmarkProcessCPU);
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legrosbuffle wrote:

Let's check `BenchmarkProcessCPU` before calling `InProcessFunctionExecutorImpl::create` and return an error right away.

https://github.com/llvm/llvm-project/pull/85168