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/utils/TableGen/CodeGenTarget.h b/utils/TableGen/CodeGenTarget.h
index bfd0863..730216c 100644
--- a/utils/TableGen/CodeGenTarget.h
+++ b/utils/TableGen/CodeGenTarget.h
@@ -19,7 +19,7 @@
 
 #include "CodeGenRegisters.h"
 #include "CodeGenInstruction.h"
-#include "Record.h"
+#include "llvm/TableGen/Record.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>