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

[Alejandro Álvarez Ayllón via cfe-commits]

alejandro-alvarez-sonarsource wrote:

I have reduced the scope of the PR, and changed the title and the description accordingly.


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