[cleanup] Refactor torque compiler to use default members.

Fixing clang-tidy warning.

Bug: v8:8015
Change-Id: I9f76c7d530b22a030c9969dfee821e0896c358fb
Reviewed-on: https://chromium-review.googlesource.com/1224171
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55989}

src/torque/ast.h

@@ -90,7 +90,7 @@ struct AstNode {
   };
 
   AstNode(Kind kind, SourcePosition pos) : kind(kind), pos(pos) {}
-  virtual ~AstNode() {}
+  virtual ~AstNode() = default;
 
   const Kind kind;
   SourcePosition pos;

src/torque/declarable.h

@@ -24,7 +24,7 @@ class Generic;
 
 class Declarable {
  public:
-  virtual ~Declarable() {}
+  virtual ~Declarable() = default;
   enum Kind {
     kVariable,
     kParameter,

src/torque/declarations.h

@@ -219,7 +219,7 @@ class Declarations::ScopedGenericScopeChainSnapshot {
   ScopedGenericScopeChainSnapshot(Declarations* declarations,
                                   const SpecializationKey& key)
       : restorer_(declarations->generic_declaration_scopes_[key.first]) {}
-  ~ScopedGenericScopeChainSnapshot() {}
+  ~ScopedGenericScopeChainSnapshot() = default;
 
  private:
   ScopeChain::ScopedSnapshotRestorer restorer_;

src/torque/source-positions.h

@@ -29,7 +29,7 @@ DECLARE_CONTEXTUAL_VARIABLE(CurrentSourcePosition, SourcePosition)
 
 class SourceFileMap : public ContextualClass<SourceFileMap> {
  public:
-  SourceFileMap() {}
+  SourceFileMap() = default;
   static const std::string& GetSource(SourceId source) {
     return Get().sources_[source.id_];
   }

src/torque/types.h

@@ -44,7 +44,7 @@ class TypeBase {
     kUnionType,
     kStructType
   };
-  virtual ~TypeBase() {}
+  virtual ~TypeBase() = default;
   bool IsAbstractType() const { return kind() == Kind::kAbstractType; }
   bool IsFunctionPointerType() const {
     return kind() == Kind::kFunctionPointerType;
@@ -344,7 +344,7 @@ inline std::ostream& operator<<(std::ostream& os, const Type& t) {
 
 class VisitResult {
  public:
-  VisitResult() {}
+  VisitResult() = default;
   VisitResult(const Type* type, const std::string& value)
       : type_(type), value_(value), declarable_{} {}
   VisitResult(const Type* type, const Value* declarable);