[ADT, Support] Use "= default" (NFC)

Identified with modernize-use-equals-default.

Author: kazutakahirata

llvm/include/llvm/ADT/AddressRanges.h

@@ -21,7 +21,7 @@ namespace llvm {
 /// a start and an end address: [Start, End).
 class AddressRange {
 public:
-  AddressRange() {}
+  AddressRange() = default;
   AddressRange(uint64_t S, uint64_t E) : Start(S), End(E) {
     assert(Start <= End);
   }

llvm/include/llvm/Support/ELFAttributeParser.h

@@ -17,7 +17,7 @@ namespace llvm {
 
 class ELFAttributeParser {
 public:
-  virtual ~ELFAttributeParser() {}
+  virtual ~ELFAttributeParser() = default;
 
   virtual Error parse(ArrayRef<uint8_t> Section, llvm::endianness Endian) {
     return llvm::Error::success();

llvm/include/llvm/Support/GraphWriter.h

@@ -128,7 +128,7 @@ template <typename GraphType, typename Derived> class GraphWriterBase {
     DTraits = DOTTraits(SN);
     RenderUsingHTML = DTraits.renderNodesUsingHTML();
   }
-  virtual ~GraphWriterBase() {}
+  virtual ~GraphWriterBase() = default;
 
   void writeGraph(const std::string &Title = "") {
     // Output the header for the graph...
@@ -369,7 +369,7 @@ class GraphWriter : public GraphWriterBase<GraphType, GraphWriter<GraphType>> {
 public:
   GraphWriter(raw_ostream &o, const GraphType &g, bool SN)
       : GraphWriterBase<GraphType, GraphWriter<GraphType>>(o, g, SN) {}
-  ~GraphWriter() override {}
+  ~GraphWriter() override = default;
 };
 
 template <typename GraphType>

llvm/lib/Support/raw_socket_stream.cpp

@@ -332,7 +332,7 @@ ListeningSocket::~ListeningSocket() {
 raw_socket_stream::raw_socket_stream(int SocketFD)
     : raw_fd_stream(SocketFD, true) {}
 
-raw_socket_stream::~raw_socket_stream() {}
+raw_socket_stream::~raw_socket_stream() = default;
 
 Expected<std::unique_ptr<raw_socket_stream>>
 raw_socket_stream::createConnectedUnix(StringRef SocketPath) {

llvm/unittests/ADT/ConcurrentHashtableTest.cpp

@@ -21,7 +21,7 @@ using namespace parallel;
 namespace {
 class String {
 public:
-  String() {}
+  String() = default;
   const std::string &getKey() const { return Data; }
 
   template <typename AllocatorTy>

llvm/unittests/ADT/DirectedGraphTest.cpp

@@ -43,7 +43,7 @@ class DGTestEdge : public DGTestEdgeBase {
 class DGTestGraph : public DGTestBase {
 public:
   DGTestGraph() = default;
-  ~DGTestGraph(){};
+  ~DGTestGraph() = default;
 };
 
 using EdgeListTy = SmallVector<DGTestEdge *, 2>;

llvm/unittests/ADT/IListTest.cpp

@@ -19,7 +19,7 @@ namespace {
 struct Node : ilist_node<Node> {
   int Value;
 
-  Node() {}
+  Node() = default;
   Node(int Value) : Value(Value) {}
   Node(const Node&) = default;
   ~Node() { Value = -1; }

llvm/unittests/ADT/SmallVectorTest.cpp

@@ -159,7 +159,7 @@ int Constructable::numCopyAssignmentCalls;
 int Constructable::numMoveAssignmentCalls;
 
 struct NonCopyable {
-  NonCopyable() {}
+  NonCopyable() = default;
   NonCopyable(NonCopyable &&) {}
   NonCopyable &operator=(NonCopyable &&) { return *this; }
 private:

llvm/unittests/ADT/StringMapTest.cpp

@@ -367,7 +367,7 @@ TEST_F(StringMapTest, NonDefaultConstructable) {
 }
 
 struct Immovable {
-  Immovable() {}
+  Immovable() = default;
   Immovable(Immovable &&) = delete; // will disable the other special members
 };
 

llvm/unittests/ADT/TypeSwitchTest.cpp

@@ -167,7 +167,7 @@ TEST(TypeSwitchTest, DefaultNullptr) {
 TEST(TypeSwitchTest, DefaultNullptrForPointerLike) {
   struct Value {
     void *ptr;
-    Value(const Value &other) : ptr(other.ptr) {}
+    Value(const Value &other) = default;
     Value(std::nullptr_t) : ptr(nullptr) {}
     Value() : Value(nullptr) {}
   };