[Bug preprocessor/71851] Get more time granularity at preprocessing

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71851

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
seeding from the current time sounds like a bad idea from a security
perspective.
why not __RANDOM__ or __SECURE_RANDOM__?