Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.

Only minor manual fixes. No functionality change intended.

llvm-svn: 273808
diff --git a/llvm/lib/Transforms/Utils/LoopSimplify.cpp b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
index 2509b0a..66aef29 100644
--- a/llvm/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
@@ -501,14 +501,13 @@
   // trip count computations.
   SmallVector<BasicBlock*, 8> ExitingBlocks;
   L->getExitingBlocks(ExitingBlocks);
-  for (SmallVectorImpl<BasicBlock *>::iterator I = ExitingBlocks.begin(),
-       E = ExitingBlocks.end(); I != E; ++I)
-    if (BranchInst *BI = dyn_cast<BranchInst>((*I)->getTerminator()))
+  for (BasicBlock *ExitingBlock : ExitingBlocks)
+    if (BranchInst *BI = dyn_cast<BranchInst>(ExitingBlock->getTerminator()))
       if (BI->isConditional()) {
         if (UndefValue *Cond = dyn_cast<UndefValue>(BI->getCondition())) {
 
           DEBUG(dbgs() << "LoopSimplify: Resolving \"br i1 undef\" to exit in "
-                       << (*I)->getName() << "\n");
+                       << ExitingBlock->getName() << "\n");
 
           BI->setCondition(ConstantInt::get(Cond->getType(),
                                             !L->contains(BI->getSuccessor(0))));
@@ -540,9 +539,7 @@
 
   SmallSetVector<BasicBlock *, 8> ExitBlockSet(ExitBlocks.begin(),
                                                ExitBlocks.end());
-  for (SmallSetVector<BasicBlock *, 8>::iterator I = ExitBlockSet.begin(),
-         E = ExitBlockSet.end(); I != E; ++I) {
-    BasicBlock *ExitBlock = *I;
+  for (BasicBlock *ExitBlock : ExitBlockSet) {
     for (pred_iterator PI = pred_begin(ExitBlock), PE = pred_end(ExitBlock);
          PI != PE; ++PI)
       // Must be exactly this loop: no subloops, parent loops, or non-loop preds