TableGen backends: use emitSourceFileHeader() to emit the warning about
file contents being autogenerated


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173979 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/ClangCommentCommandInfoEmitter.cpp b/utils/TableGen/ClangCommentCommandInfoEmitter.cpp
index 36fbcd4..70821ff 100644
--- a/utils/TableGen/ClangCommentCommandInfoEmitter.cpp
+++ b/utils/TableGen/ClangCommentCommandInfoEmitter.cpp
@@ -7,20 +7,22 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This tablegen backend emits command lists and efficient matchers command
+// This tablegen backend emits command lists and efficient matchers for command
 // names that are used in documentation comments.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/StringMatcher.h"
+#include "llvm/TableGen/TableGenBackend.h"
 #include <vector>
 
 using namespace llvm;
 
 namespace clang {
 void EmitClangCommentCommandInfo(RecordKeeper &Records, raw_ostream &OS) {
-  OS << "// This file is generated by TableGen.  Do not edit.\n\n";
+  emitSourceFileHeader("A list of commands useable in documentation "
+                       "comments", OS);
 
   OS << "namespace {\n"
         "const CommandInfo Commands[] = {\n";