Suspicious changes to Serialization

From: Peter Dimov (pdimov_at_[hidden])
Date: 2024-03-14 00:26:45

The current Serialization emits the following warning:

c:\projects\boost-root\boost\serialization\extended_type_info_typeid.hpp(118) : warning C4700: uninitialized local variable 'ap' used

which looks legitimate and is caused by the removal of `va_start(ap, count);` in this commit

https://github.com/boostorg/serialization/commit/2805bc3faa8f8fb7ce80ec518158563c5fcf26f6

This looks like a mistake to me, and is probably going to cause problems.