[clang] [clang][analyzer] StreamChecker: Model getc, vfscanf, putc, vfprintf (PR #82476)

[Balázs Kéri via cfe-commits]

https://github.com/balazske requested changes to this pull request.

I would like better if the new tests that are invalidation-related are moved to file **stream-invalidate.c** (this was added in the recent commit).

https://github.com/llvm/llvm-project/pull/82476