[turbofan] Cleanup Schedule and related classes.

test/cctest/compiler/test-instruction.cc

Index: test/cctest/compiler/test-instruction.cc
diff --git a/test/cctest/compiler/test-instruction.cc b/test/cctest/compiler/test-instruction.cc
index f1c9bcdb4afed0b3942e9a05b531e6f6c9fd2f14..e6e44ea1748c587d6db835d1d2e47e2a4cb0159b 100644
--- a/test/cctest/compiler/test-instruction.cc
+++ b/test/cctest/compiler/test-instruction.cc
@@ -131,10 +131,7 @@ TEST(InstructionBasic) {
   BasicBlockVector* blocks = R.schedule.rpo_order();
   CHECK_EQ(static_cast<int>(blocks->size()), R.code->InstructionBlockCount());
 
-  int index = 0;
-  for (BasicBlockVectorIter i = blocks->begin(); i != blocks->end();
-       i++, index++) {
-    BasicBlock* block = *i;
+  for (auto block : *blocks) {
     CHECK_EQ(block->rpo_number(), R.BlockAt(block)->rpo_number().ToInt());
     CHECK_EQ(block->id().ToInt(), R.BlockAt(block)->id().ToInt());
     CHECK_EQ(NULL, block->loop_end());