[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-cov/CodeCoverage.cpp b/llvm/tools/llvm-cov/CodeCoverage.cpp
index 981c93a..ed87e9e 100644
--- a/llvm/tools/llvm-cov/CodeCoverage.cpp
+++ b/llvm/tools/llvm-cov/CodeCoverage.cpp
@@ -446,7 +446,7 @@
     error(InputPath, EC.message());
     return;
   }
-  tool_output_file InputTOF{InputPath, InputFD};
+  ToolOutputFile InputTOF{InputPath, InputFD};
 
   unsigned NumSymbols = 0;
   for (const auto &Function : Coverage.getCoveredFunctions()) {
@@ -464,7 +464,7 @@
     error(OutputPath, EC.message());
     return;
   }
-  tool_output_file OutputTOF{OutputPath, OutputFD};
+  ToolOutputFile OutputTOF{OutputPath, OutputFD};
   OutputTOF.os().close();
 
   // Invoke the demangler.