SuccessChanges

Summary

  1. [debugserver] Switch back to std::once_flag (details)
Commit 83ee8d4463d1bb1d2248f5cc7f5577672d3ddf94 by Jonas Devlieghere
[debugserver] Switch back to std::once_flag
We cannot use llvm::once_flag in debugserver because doesn't link
against llvm.
llvm-svn: 369621
The file was modifiedlldb/tools/debugserver/source/MacOSX/DarwinLog/DarwinLogCollector.cpp