Attempt two at fixing threading on Windows

Reviewers: compnerd

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D28735

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292027 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed