[CodeGen] Use range-based for loops (NFC) (#138488)

This is a reland of #138434 except that:

- the bits for llvm/lib/CodeGen/RenameIndependentSubregs.cpp
  have been dropped because they caused a test failure under asan, and

- the bits for llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp have
  been improved with structured bindings.

1 files changed, 2 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp b/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp
index 6bbd130..5d6e7f1 100644
--- a/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp
+++ b/llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp
@@ -2588,8 +2588,7 @@ void InstrRefBasedLDV::placeMLocPHIs(
   auto CollectPHIsForLoc = [&](LocIdx L) {
     // Collect the set of defs.
     SmallPtrSet<MachineBasicBlock *, 32> DefBlocks;
-    for (unsigned int I = 0; I < OrderToBB.size(); ++I) {
-      MachineBasicBlock *MBB = OrderToBB[I];
+    for (MachineBasicBlock *MBB : OrderToBB) {
       const auto &TransferFunc = MLocTransfer[MBB->getNumber()];
       if (TransferFunc.contains(L))
         DefBlocks.insert(MBB);
@@ -3800,8 +3799,7 @@ bool InstrRefBasedLDV::ExtendRanges(MachineFunction &MF,
   // To mirror old LiveDebugValues, enumerate variables in RPOT order. Otherwise
   // the order is unimportant, it just has to be stable.
   unsigned VarAssignCount = 0;
-  for (unsigned int I = 0; I < OrderToBB.size(); ++I) {
-    auto *MBB = OrderToBB[I];
+  for (MachineBasicBlock *MBB : OrderToBB) {
     auto *VTracker = &vlocs[MBB->getNumber()];
     // Collect each variable with a DBG_VALUE in this block.
     for (auto &idx : VTracker->Vars) {