[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-dis/llvm-dis.cpp b/llvm/tools/llvm-dis/llvm-dis.cpp
index 6828b69..c91aa1c 100644
--- a/llvm/tools/llvm-dis/llvm-dis.cpp
+++ b/llvm/tools/llvm-dis/llvm-dis.cpp
@@ -191,8 +191,8 @@
   }
 
   std::error_code EC;
-  std::unique_ptr<tool_output_file> Out(
-      new tool_output_file(OutputFilename, EC, sys::fs::F_None));
+  std::unique_ptr<ToolOutputFile> Out(
+      new ToolOutputFile(OutputFilename, EC, sys::fs::F_None));
   if (EC) {
     errs() << EC.message() << '\n';
     return 1;