[sanitizer] Resubmit D66620 from monorepo

Summary: https://reviews.llvm.org/D66620 is accepted but was based on the multi-repo setup, so I was not able to `arc patch` it. Resubmit the diff under monorepo

Committed on behalf of @sugak (Igor Sugak)

Reviewers: sugak

Subscribers: #sanitizers, llvm-commits, vitalybuka

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D66624

llvm-svn: 369716