[ThinLTO] Re-commit of dot dumper after test fix

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323116 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/ModuleSummaryAnalysis.cpp

@@ -372,7 +372,7 @@ ModuleSummaryIndex llvm::buildModuleSummaryIndex(
     std::function<BlockFrequencyInfo *(const Function &F)> GetBFICallback,
     ProfileSummaryInfo *PSI) {
   assert(PSI);
-  ModuleSummaryIndex Index;
+  ModuleSummaryIndex Index(/*IsPerformingAnalysis=*/true);
 
   // Identify the local values in the llvm.used and llvm.compiler.used sets,
   // which should not be exported as they would then require renaming and