[llvm] [BOLT][NFC] Add sink block to flow CFG in profile inference (PR #95047)

[Amir Ayupov via llvm-commits]

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@@ -320,11 +318,19 @@ createFlowFunction(const BinaryFunction::BasicBlockOrderType &BlockOrder) {
     Func.Blocks.emplace_back();
     FlowBlock &Block = Func.Blocks.back();
     Block.Index = Func.Blocks.size() - 1;
+    if (BB->successors().empty())
+      Block.IsExit = true;
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aaupov wrote:

```suggestion
    Block.IsExit = BB->successors().empty();
```

https://github.com/llvm/llvm-project/pull/95047