[llvm-profdata] Fix assertion from invalid iterator

llvm/tools/llvm-profdata/llvm-profdata.cpp

void SampleOverlapAggregator::computeSampleProfileOverlap(raw_fd_ostream &OS) {
   for (const auto &TestFunc : TestProfiles) {
     SampleOverlapStats FuncOverlap;
     FuncOverlap.TestName = TestFunc.second.getContext();
     assert(TestStats.count(FuncOverlap.TestName) &&
            "TestStats should have records for all functions in test profile "
            "except inlinees");
     FuncOverlap.TestSample = TestStats[FuncOverlap.TestName].SampleSum;
 
+    bool Matched = false;
     const auto Match = BaseFuncProf.find(FuncOverlap.TestName);
     if (Match == BaseFuncProf.end()) {
       const FuncSampleStats &FuncStats = TestStats[FuncOverlap.TestName];
       ++ProfOverlap.TestUniqueCount;
       ProfOverlap.TestUniqueSample += FuncStats.SampleSum;
       FuncOverlap.TestUniqueSample = FuncStats.SampleSum;
 
       updateHotBlockOverlap(0, FuncStats.SampleSum, FuncStats.HotBlockCount);
if (Match == BaseFuncProf.end()) {
       // Accumulate the percentage of base unique and test unique samples into
       // ProfOverlap.
       ProfOverlap.BaseUniqueSample += FuncOverlap.BaseUniqueSample;
       ProfOverlap.TestUniqueSample += FuncOverlap.TestUniqueSample;
 
       // Remove matched base functions for later reporting functions not found
       // in test profile.
       BaseFuncProf.erase(Match);
+      Matched = true;
     }
 
     // Print function-level similarity information if specified by options.
     assert(TestStats.count(FuncOverlap.TestName) &&
            "TestStats should have records for all functions in test profile "
            "except inlinees");
     if (TestStats[FuncOverlap.TestName].MaxSample >= FuncFilter.ValueCutoff ||
-        (Match != BaseFuncProf.end() &&
-         FuncOverlap.Similarity < LowSimilarityThreshold) ||
-        (Match != BaseFuncProf.end() && !FuncFilter.NameFilter.empty() &&
+        (Matched && FuncOverlap.Similarity < LowSimilarityThreshold) ||
+        (Matched && !FuncFilter.NameFilter.empty() &&
          FuncOverlap.BaseName.toString().find(FuncFilter.NameFilter) !=
              std::string::npos)) {
       assert(ProfOverlap.BaseSample > 0 &&
              "Total samples in base profile should be greater than 0");
       FuncOverlap.BaseWeight =
           static_cast<double>(FuncOverlap.BaseSample) / ProfOverlap.BaseSample;
       assert(ProfOverlap.TestSample > 0 &&
              "Total samples in test profile should be greater than 0");