Add new interceptors: getprotoent(3) family

Summary:
getprotoent, getprotobynumber, getprotobyname - get protocol entry

Reuse them on NetBSD.

Sponsored by <The NetBSD Foundation>

Reviewers: joerg, vitalybuka

Reviewed By: vitalybuka

Subscribers: kubamracek, llvm-commits, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D43541

llvm-svn: 326162