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/lib/Bitcode/Writer/BitWriter.cpp b/lib/Bitcode/Writer/BitWriter.cpp
index 985208c..cd1ada2 100644
--- a/lib/Bitcode/Writer/BitWriter.cpp
+++ b/lib/Bitcode/Writer/BitWriter.cpp
@@ -18,7 +18,7 @@
 
 int LLVMWriteBitcodeToFile(LLVMModuleRef M, const char *Path) {
   std::string ErrorInfo;
-  raw_fd_ostream OS(Path, ErrorInfo, raw_fd_ostream::F_Binary);
+  raw_fd_ostream OS(Path, ErrorInfo, sys::fs::F_Binary);
 
   if (!ErrorInfo.empty())
     return -1;