[3.7] bpo-35214: Annotate posix calls for clang MSan. (GH-11389) (GH-11391)

It doesn't know the details of a few less common libc functions..

(cherry picked from commit 1d300ce1d8238136595c8fea76266a4755cd73a2)

Co-authored-by: Gregory P. Smith <greg@krypto.org> [Google]
2 files changed