[clang] [clang][analyzer] Support 'tello' and 'fseeko' in the StreamChecker (PR #77580)

[Balázs Kéri via cfe-commits]

balazske wrote:

It is better to replace in code of `evalFtell` the `C.getASTContext().LongTy` with `Call.getResultType()` (occurs 2 times), this is more exact if `off_t` is defined to something else than `long`.

https://github.com/llvm/llvm-project/pull/77580