[IR] Use range-based for loops (NFC) (#97950)

Author: kazutakahirata

llvm/lib/IR/AsmWriter.cpp

@@ -1021,8 +1021,8 @@ void SlotTracker::processModule() {
 
   // Add metadata used by named metadata.
   for (const NamedMDNode &NMD : TheModule->named_metadata()) {
-    for (unsigned i = 0, e = NMD.getNumOperands(); i != e; ++i)
-      CreateMetadataSlot(NMD.getOperand(i));
+    for (const MDNode *N : NMD.operands())
+      CreateMetadataSlot(N);
   }
 
   for (const Function &F : *TheModule) {

llvm/lib/IR/Module.cpp

@@ -387,8 +387,7 @@ void Module::setModuleFlag(ModFlagBehavior Behavior, StringRef Key,
                            Metadata *Val) {
   NamedMDNode *ModFlags = getOrInsertModuleFlagsMetadata();
   // Replace the flag if it already exists.
-  for (unsigned I = 0, E = ModFlags->getNumOperands(); I != E; ++I) {
-    MDNode *Flag = ModFlags->getOperand(I);
+  for (MDNode *Flag : ModFlags->operands()) {
     ModFlagBehavior MFB;
     MDString *K = nullptr;
     Metadata *V = nullptr;