Libraries: Use default constructors/destructors in LibCoredump

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/LibCoredump/Reader.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -76,10 +77,6 @@ Optional<ByteBuffer> Reader::decompress_coredump(ReadonlyBytes raw_coredump)
     return bytebuffer.release_value();
 }
 
-Reader::~Reader()
-{
-}
-
 Reader::NotesEntryIterator::NotesEntryIterator(const u8* notes_data)
     : m_current(bit_cast<const ELF::Core::NotesEntry*>(notes_data))
     , start(notes_data)