Rename F_{None,Text,Append} to OF_{None,Text,Append}. NFC

F_{None,Text,Append} are kept for compatibility since r334221.

llvm-svn: 367800
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index e1b08db..4b6775d 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4042,7 +4042,7 @@
   // Overwrite the timestamp file contents so that file's mtime changes.
   std::string TimestampFilename = MF.getTimestampFilename();
   std::error_code EC;
-  llvm::raw_fd_ostream OS(TimestampFilename, EC, llvm::sys::fs::F_Text);
+  llvm::raw_fd_ostream OS(TimestampFilename, EC, llvm::sys::fs::OF_Text);
   if (EC)
     return;
   OS << "Timestamp file\n";