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/tools/bugpoint/OptimizerDriver.cpp b/tools/bugpoint/OptimizerDriver.cpp
index 36d536a..0c39b9d 100644
--- a/tools/bugpoint/OptimizerDriver.cpp
+++ b/tools/bugpoint/OptimizerDriver.cpp
@@ -68,7 +68,7 @@
 bool BugDriver::writeProgramToFile(const std::string &Filename,
                                    const Module *M) const {
   std::string ErrInfo;
-  tool_output_file Out(Filename.c_str(), ErrInfo, raw_fd_ostream::F_Binary);
+  tool_output_file Out(Filename.c_str(), ErrInfo, sys::fs::F_Binary);
   if (ErrInfo.empty())
     return writeProgramToFileAux(Out, M);
   return true;