Add new interceptor: lstat(2)

Summary:
lstat - get file status

Use it on NetBSD.

Sponsored by <The NetBSD Foundation>

Reviewers: joerg, vitalybuka, eugenis

Reviewed By: vitalybuka

Subscribers: kubamracek, llvm-commits, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D42909

llvm-svn: 325199