Libraries: Use default constructors/destructors in LibJS

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/Libraries/LibJS/Runtime/BooleanObject.cpp

@@ -19,9 +19,4 @@ BooleanObject::BooleanObject(bool value, Object& prototype)
     , m_value(value)
 {
 }
-
-BooleanObject::~BooleanObject()
-{
-}
-
 }