Add a wrapper for open.

This centralizes the handling of O_BINARY and opens the way for hiding more
differences (like how open behaves with directories).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186447 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/FileUpdate/FileUpdate.cpp b/utils/FileUpdate/FileUpdate.cpp
index 6f9544f..fbcd927 100644
--- a/utils/FileUpdate/FileUpdate.cpp
+++ b/utils/FileUpdate/FileUpdate.cpp
@@ -71,7 +71,7 @@
            << "', contents changed.\n";
   std::string ErrorStr;
   tool_output_file OutStream(OutputFilename.c_str(), ErrorStr,
-                             raw_fd_ostream::F_Binary);
+                             sys::fs::F_Binary);
   if (!ErrorStr.empty()) {
     errs() << argv[0] << ": Unable to write output '"
            << OutputFilename << "': " << ErrorStr << '\n';