Link sanitized programs on NetBSD with -lkvm

Summary:
kvm - kernel memory interface

The kvm(3) functions like kvm_open(), kvm_getargv() or kvm_getenvv()
are used in programs that can request information about a kernel and
its processes. The LLVM sanitizers will make use of them on NetBSD.

Sponsored by <The NetBSD Foundation>

Reviewers: joerg, vitalybuka, dvyukov

Reviewed By: vitalybuka

Subscribers: llvm-commits, cfe-commits, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D42017

llvm-svn: 323022