Support the localtime interceptor for NetBSD

Summary:
The localtime symbol is mangled to __locatime50
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/D42045

llvm-svn: 323019