tidy: modernize-use-equals-default

src/support/lockedpool.cpp

@@ -46,9 +46,7 @@ Arena::Arena(void *base_in, size_t size_in, size_t alignment_in):
     chunks_free_end.emplace(static_cast<char*>(base) + size_in, it);
 }
 
-Arena::~Arena()
-{
-}
+Arena::~Arena() = default;
 
 void* Arena::alloc(size_t size)
 {