[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/tools/llvm-mc/llvm-mc.cpp b/llvm/tools/llvm-mc/llvm-mc.cpp
index ec4c5d5..dcd74a6 100644
--- a/llvm/tools/llvm-mc/llvm-mc.cpp
+++ b/llvm/tools/llvm-mc/llvm-mc.cpp
@@ -197,13 +197,13 @@
   return TheTarget;
 }
 
-static std::unique_ptr<tool_output_file> GetOutputStream() {
+static std::unique_ptr<ToolOutputFile> GetOutputStream() {
   if (OutputFilename == "")
     OutputFilename = "-";
 
   std::error_code EC;
-  auto Out = llvm::make_unique<tool_output_file>(OutputFilename, EC,
-                                                 sys::fs::F_None);
+  auto Out =
+      llvm::make_unique<ToolOutputFile>(OutputFilename, EC, sys::fs::F_None);
   if (EC) {
     errs() << EC.message() << '\n';
     return nullptr;
@@ -534,7 +534,7 @@
     FeaturesStr = Features.getString();
   }
 
-  std::unique_ptr<tool_output_file> Out = GetOutputStream();
+  std::unique_ptr<ToolOutputFile> Out = GetOutputStream();
   if (!Out)
     return 1;