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

lib/Support/ToolOutputFile.cpp

@@ -37,9 +37,8 @@ tool_output_file::CleanupInstaller::~CleanupInstaller() {
 }
 
 tool_output_file::tool_output_file(const char *filename, std::string &ErrorInfo,
-                                   unsigned Flags)
-  : Installer(filename),
-    OS(filename, ErrorInfo, Flags) {
+                                   sys::fs::OpenFlags Flags)
+    : Installer(filename), OS(filename, ErrorInfo, Flags) {
   // If open fails, no cleanup is needed.
   if (!ErrorInfo.empty())
     Installer.Keep = true;