[Transforms] Use "= default" (NFC) (llvm#166043)

Identified with modernize-use-equals-default.

Author: kazutakahirata

llvm/include/llvm/Transforms/Coroutines/CoroAnnotationElide.h

@@ -24,7 +24,7 @@
 namespace llvm {
 
 struct CoroAnnotationElidePass : PassInfoMixin<CoroAnnotationElidePass> {
-  CoroAnnotationElidePass() {}
+  CoroAnnotationElidePass() = default;
 
   PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM,
                         LazyCallGraph &CG, CGSCCUpdateResult &UR);

llvm/include/llvm/Transforms/IPO/FatLTOCleanup.h

@@ -26,7 +26,7 @@ class ModuleSummaryIndex;
 
 class FatLtoCleanup : public PassInfoMixin<FatLtoCleanup> {
 public:
-  FatLtoCleanup() {}
+  FatLtoCleanup() = default;
   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
   static bool isRequired() { return true; }
 };

llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Legality.h

@@ -167,7 +167,7 @@ class LegalityResult {
   LegalityResult &operator=(const LegalityResult &) = delete;
 
 public:
-  virtual ~LegalityResult() {}
+  virtual ~LegalityResult() = default;
   LegalityResultID getSubclassID() const { return ID; }
 #ifndef NDEBUG
   virtual void print(raw_ostream &OS) const {

llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/SeedCollector.h

@@ -36,7 +36,7 @@ class SeedBundle {
   /// No need to allow copies.
   SeedBundle(const SeedBundle &) = delete;
   SeedBundle &operator=(const SeedBundle &) = delete;
-  virtual ~SeedBundle() {}
+  virtual ~SeedBundle() = default;
 
   using iterator = SmallVector<Instruction *>::iterator;
   using const_iterator = SmallVector<Instruction *>::const_iterator;

llvm/lib/Transforms/Coroutines/CoroCloner.h

@@ -77,7 +77,7 @@ class BaseCloner {
       : OrigF(OrigF), Suffix(Suffix), Shape(Shape), FKind(FKind),
         Builder(OrigF.getContext()), TTI(TTI) {}
 
-  virtual ~BaseCloner() {}
+  virtual ~BaseCloner() = default;
 
   /// Create a clone for a continuation lowering.
   static Function *createClone(Function &OrigF, const Twine &Suffix,

llvm/lib/Transforms/Scalar/GVNSink.cpp

@@ -514,7 +514,7 @@ class ValueTable {
 
 class GVNSink {
 public:
-  GVNSink() {}
+  GVNSink() = default;
 
   bool run(Function &F) {
     LLVM_DEBUG(dbgs() << "GVNSink: running on function @" << F.getName()

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -939,7 +939,7 @@ class VPIRMetadata {
   SmallVector<std::pair<unsigned, MDNode *>> Metadata;
 
 public:
-  VPIRMetadata() {}
+  VPIRMetadata() = default;
 
   /// Adds metatadata that can be preserved from the original instruction
   /// \p I.
@@ -950,12 +950,9 @@ class VPIRMetadata {
   VPIRMetadata(Instruction &I, LoopVersioning *LVer);
 
   /// Copy constructor for cloning.
-  VPIRMetadata(const VPIRMetadata &Other) : Metadata(Other.Metadata) {}
+  VPIRMetadata(const VPIRMetadata &Other) = default;
 
-  VPIRMetadata &operator=(const VPIRMetadata &Other) {
-    Metadata = Other.Metadata;
-    return *this;
-  }
+  VPIRMetadata &operator=(const VPIRMetadata &Other) = default;
 
   /// Add all metadata to \p I.
   void applyMetadata(Instruction &I) const;
@@ -3985,7 +3982,7 @@ class VPIRBasicBlock : public VPBasicBlock {
         IRBB(IRBB) {}
 
 public:
-  ~VPIRBasicBlock() override {}
+  ~VPIRBasicBlock() override = default;
 
   static inline bool classof(const VPBlockBase *V) {
     return V->getVPBlockID() == VPBlockBase::VPIRBasicBlockSC;
@@ -4037,7 +4034,7 @@ class LLVM_ABI_FOR_TEST VPRegionBlock : public VPBlockBase {
         IsReplicator(IsReplicator) {}
 
 public:
-  ~VPRegionBlock() override {}
+  ~VPRegionBlock() override = default;
 
   /// Method to support type inquiry through isa, cast, and dyn_cast.
   static inline bool classof(const VPBlockBase *V) {