[AMDGPU] Fixes -Wrange-loop-analysis warnings

[Mordante]

Summary

This avoids new warnings due to D68912 adds -Wrange-loop-analysis to -Wall.

[aaron.ballman]

LGTM with a request to drop top-level consts

llvm/lib/Target/AMDGPU/AMDGPUMachineCFGStructurizer.cpp

865

Drop top-level const here and elsewhere?

llvm/lib/Target/AMDGPU/AMDGPUMachineCFGStructurizer.cpp

if (CurrentTopRegion == nullptr) {
     }
   }
 }
 
 #ifndef NDEBUG
 void LinearizedRegion::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
   OS << "Linearized Region {";
   bool IsFirst = true;
-  for (const auto &MBB : MBBs) {
+  for (auto MBB : MBBs) {
     if (IsFirst) {
       IsFirst = false;
     } else {
       OS << " ,";
     }
     OS << MBB->getNumber();
   }
   OS << "} (" << Entry->getNumber() << ", "

 
 void LinearizedRegion::setExit(MachineBasicBlock *NewExit) { Exit = NewExit; }
 
 MachineBasicBlock *LinearizedRegion::getExit() { return Exit; }
 
 void LinearizedRegion::addMBB(MachineBasicBlock *MBB) { MBBs.insert(MBB); }
 
 void LinearizedRegion::addMBBs(LinearizedRegion *InnerRegion) {
-  for (const auto &MBB : InnerRegion->MBBs) {
+  for (auto MBB : InnerRegion->MBBs) {
     addMBB(MBB);
   }
 }
 
 bool LinearizedRegion::contains(MachineBasicBlock *MBB) {
   return MBBs.count(MBB) == 1;
 }
 

llvm/lib/Target/AMDGPU/AMDGPUUnifyMetadata.cpp

private:
     /// Keep the largest version as the sole operand if PickFirst is false.
     /// Otherwise pick it from the first value, representing kernel module.
     bool unifyVersionMD(Module &M, StringRef Name, bool PickFirst) {
       auto NamedMD = M.getNamedMetadata(Name);
       if (!NamedMD || NamedMD->getNumOperands() <= 1)
         return false;
       MDNode *MaxMD = nullptr;
       auto MaxVer = 0U;
-      for (const auto &VersionMD : NamedMD->operands()) {
+      for (auto VersionMD : NamedMD->operands()) {
         assert(VersionMD->getNumOperands() == 2);
         auto CMajor = mdconst::extract<ConstantInt>(VersionMD->getOperand(0));
         auto VersionMajor = CMajor->getZExtValue();
         auto CMinor = mdconst::extract<ConstantInt>(VersionMD->getOperand(1));
         auto VersionMinor = CMinor->getZExtValue();
         auto Ver = (VersionMajor * 100) + (VersionMinor * 10);
         if (Ver > MaxVer) {
           MaxVer = Ver;
namespace {
   /// !n2 = !{!"cl_khr_image"}
   /// Combine it into a single list with unique operands.
   bool unifyExtensionMD(Module &M, StringRef Name) {
     auto NamedMD = M.getNamedMetadata(Name);
     if (!NamedMD || NamedMD->getNumOperands() == 1)
       return false;
 
     SmallVector<Metadata *, 4> All;
-    for (const auto &MD : NamedMD->operands())
+    for (auto MD : NamedMD->operands())
       for (const auto &Op : MD->operands())
         if (std::find(All.begin(), All.end(), Op.get()) == All.end())
           All.push_back(Op.get());
 
     NamedMD->eraseFromParent();
     NamedMD = M.getOrInsertNamedMetadata(Name);
     for (const auto &MD : All)
       NamedMD->addOperand(MDNode::get(M.getContext(), MD));