Utilities: Use default constructors/destructors

https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#cother-other-default-operation-rules

"The compiler is more likely to get the default semantics right and
you cannot implement these functions better than the compiler."

Userland/Utilities/expr.cpp

@@ -58,7 +58,7 @@ public:
     virtual int integer() const = 0;
     virtual String string() const = 0;
     virtual Type type() const = 0;
-    virtual ~Expression() { }
+    virtual ~Expression() = default;
 };
 
 class ValueExpression : public Expression {
@@ -75,7 +75,7 @@ public:
     {
     }
 
-    virtual ~ValueExpression() { }
+    virtual ~ValueExpression() {};
 
 private:
     virtual bool truth() const override

Userland/Utilities/find.cpp

@@ -90,7 +90,7 @@ struct FileData {
 
 class Command {
 public:
-    virtual ~Command() { }
+    virtual ~Command() = default;
     virtual bool evaluate(FileData& file_data) const = 0;
 };
 

Userland/Utilities/test.cpp

@@ -30,7 +30,7 @@ bool g_there_was_an_error = false;
 
 class Condition {
 public:
-    virtual ~Condition() { }
+    virtual ~Condition() = default;
     virtual bool check() const = 0;
 };