Move TableGen's parser and entry point into a library

This is the first step towards splitting LLVM and Clang's tblgen executables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140951 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/TableGen/TableGenBackend.cpp b/lib/TableGen/TableGenBackend.cpp
new file mode 100644
index 0000000..29588db
--- /dev/null
+++ b/lib/TableGen/TableGenBackend.cpp
@@ -0,0 +1,25 @@
+//===- TableGenBackend.cpp - Base class for TableGen Backends ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides useful services for TableGen backends...
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/TableGen/TableGenBackend.h"
+#include "llvm/TableGen/Record.h"
+using namespace llvm;
+
+void TableGenBackend::EmitSourceFileHeader(const std::string &Desc,
+                                           raw_ostream &OS) const {
+  OS << "//===- TableGen'erated file -------------------------------------*-"
+       " C++ -*-===//\n//\n// " << Desc << "\n//\n// Automatically generate"
+       "d file, do not edit!\n//\n//===------------------------------------"
+       "----------------------------------===//\n\n";
+}
+