[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-modextract/llvm-modextract.cpp b/llvm/tools/llvm-modextract/llvm-modextract.cpp
index 58cede1..b2d21c2 100644
--- a/llvm/tools/llvm-modextract/llvm-modextract.cpp
+++ b/llvm/tools/llvm-modextract/llvm-modextract.cpp
@@ -54,8 +54,8 @@
   }
 
   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));
   ExitOnErr(errorCodeToError(EC));
 
   if (BinaryExtract) {