[llvm] [BOLT] Drop parsing sample PC when processing LBR perf data (PR #123420)

[Alexander Yermolovich via llvm-commits]

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@@ -1472,9 +1383,9 @@ std::error_code DataAggregator::printLBRHeatMap() {
 uint64_t DataAggregator::parseLBRSample(const PerfBranchSample &Sample,
                                         bool NeedsSkylakeFix) {
   uint64_t NumTraces{0};
-  // LBRs are stored in reverse execution order. NextPC refers to the next
-  // recorded executed PC.
-  uint64_t NextPC = opts::UseEventPC ? Sample.PC : 0;
+  // LBRs are stored in reverse execution order. NextLBR refers to the next
+  // executed branch record.
+  const LBREntry *NextLBR{nullptr};
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ayermolo wrote:

= nullptr for consistency? 

https://github.com/llvm/llvm-project/pull/123420