LWG4388 Align new definition of va_start with C23

[jwakely]

https://cplusplus.github.io/LWG/issue4388

https://wg21.link/cstdarg.syn

[JeffGarland]

@jwakely to update issue wth additional context indicating that the change provides the abiltiy to diagnose -- and update if it's possible gcc team thinks always diagnosing is possble. This will need to be seen by core

[bstamour]

Poll: Accept the resolution in LWG4388, move to immediate and send it to CWG for confirmation.

F	A	N
8	0	0

[jensmaurer]

CWG 2025-11-05: Approved.