Add new interceptors: access(2), faccessat(2)

Summary:
access, faccessat - check access permissions of a file or pathname

Sponsored by <The NetBSD Foundation>

Reviewers: joerg, vitalybuka

Reviewed By: vitalybuka

Subscribers: llvm-commits, kubamracek, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D42065

llvm-svn: 322831