[Support] Rename tool_output_file to ToolOutputFile, NFC

This class isn't similar to anything from the STL, so it shouldn't use
the STL naming conventions.

llvm-svn: 314050
diff --git a/llvm/lib/Object/ArchiveWriter.cpp b/llvm/lib/Object/ArchiveWriter.cpp
index 19a46c0..b36b256 100644
--- a/llvm/lib/Object/ArchiveWriter.cpp
+++ b/llvm/lib/Object/ArchiveWriter.cpp
@@ -394,7 +394,7 @@
                                           TmpArchiveFD, TmpArchive))
     return errorCodeToError(EC);
 
-  tool_output_file Output(TmpArchive, TmpArchiveFD);
+  ToolOutputFile Output(TmpArchive, TmpArchiveFD);
   raw_fd_ostream &Out = Output.os();
   if (Thin)
     Out << "!<thin>\n";