Use empty() instead of begin() == end().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54780 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/LoopExtractor.cpp

@@ -79,7 +79,7 @@ bool LoopExtractor::runOnFunction(Function &F) {
   LoopInfo &LI = getAnalysis<LoopInfo>();
 
   // If this function has no loops, there is nothing to do.
-  if (LI.begin() == LI.end())
+  if (LI.empty())
     return false;
 
   DominatorTree &DT = getAnalysis<DominatorTree>();