discard BB profiles with a hash of 0

Author: Jinjie-Huang

bolt/lib/Profile/DataAggregator.cpp

@@ -2417,6 +2417,7 @@ std::error_code DataAggregator::writeBATYAML(BinaryContext &BC,
       // Skip printing if there's no profile data
       llvm::erase_if(
           YamlBF.Blocks, [](const yaml::bolt::BinaryBasicBlockProfile &YamlBB) {
+            if ((size_t)YamlBB.Hash == 0) return true;
             auto HasCount = [](const auto &SI) { return SI.Count; };
             bool HasAnyCount = YamlBB.ExecCount ||
                                llvm::any_of(YamlBB.Successors, HasCount) ||