Fix bot failure from r347145

The #if check around the statistics computation gave an error about
the statistic being an unused variable. Instead, guard with
AreStatisticsEnabled().

llvm-svn: 347146
diff --git a/llvm/lib/IR/ModuleSummaryIndex.cpp b/llvm/lib/IR/ModuleSummaryIndex.cpp
index bb5b7d0..e51d69b 100644
--- a/llvm/lib/IR/ModuleSummaryIndex.cpp
+++ b/llvm/lib/IR/ModuleSummaryIndex.cpp
@@ -166,14 +166,13 @@
           GVS->setReadOnly(false);
       propagateConstantsToRefs(S.get());
     }
-#if LLVM_ENABLE_STATS
-  for (auto &P : *this)
-    if (P.second.SummaryList.size())
-      if (auto *GVS = dyn_cast<GlobalVarSummary>(
-              P.second.SummaryList[0]->getBaseObject()))
-        if (isGlobalValueLive(GVS) && GVS->isReadOnly())
-          ReadOnlyLiveGVars++;
-#endif
+  if (llvm::AreStatisticsEnabled())
+    for (auto &P : *this)
+      if (P.second.SummaryList.size())
+        if (auto *GVS = dyn_cast<GlobalVarSummary>(
+                P.second.SummaryList[0]->getBaseObject()))
+          if (isGlobalValueLive(GVS) && GVS->isReadOnly())
+            ReadOnlyLiveGVars++;
 }
 
 // TODO: write a graphviz dumper for SCCs (see ModuleSummaryIndex::exportToDot)