[llvm] Use llvm::fill (NFC) (#147099)

We can pass a range to llvm::fill.

Author: kazutakahirata

llvm/include/llvm/IR/LegacyPassManagers.h

@@ -333,8 +333,7 @@ class LLVM_ABI PMDataManager {
   /// Initialize available analysis information.
   void initializeAnalysisInfo() {
     AvailableAnalysis.clear();
-    for (auto &IA : InheritedAnalysis)
-      IA = nullptr;
+    llvm::fill(InheritedAnalysis, nullptr);
   }
 
   // Return true if P preserves high level analysis used by other

llvm/lib/DWARFLinker/Parallel/DWARFLinkerCompileUnit.cpp

@@ -101,10 +101,8 @@ void CompileUnit::maybeResetToLoadedStage() {
   OutUnitDIE = nullptr;
   DebugAddrIndexMap.clear();
 
-  for (uint64_t &Offset : OutDieOffsetArray)
-    Offset = 0;
-  for (TypeEntry *&Name : TypeEntries)
-    Name = nullptr;
+  llvm::fill(OutDieOffsetArray, 0);
+  llvm::fill(TypeEntries, nullptr);
   eraseSections();
 
   setStage(Stage::CreatedNotLoaded);

llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp

@@ -105,8 +105,7 @@ namespace {
     };
 
     LatticeCell() : Kind(Top), Size(0), IsSpecial(false) {
-      for (const Constant *&Value : Values)
-        Value = nullptr;
+      llvm::fill(Values, nullptr);
     }
 
     bool meet(const LatticeCell &L);