[Analyzer][StreamChecker] Introduction of stream error handling.
Summary:
Store the error flags (EOF or error) of a stream.
Support the functions feof, ferror, clearerr.
Added a test checker for setting the error flags.
Reviewers: Szelethus, NoQ, Charusso, baloghadamsoftware, xazax.hun
Reviewed By: Szelethus
Subscribers: steakhal, ASDenysPetrov, rnkovacs, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, gamesh411, Charusso, martong, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D75682