Unify Options.td and CC1Options.td, in a first step towards unifying the serialization logic in Frontend and Driver.

Reviewed by Eric, Doug and Chandler, and here: http://llvm.org/reviews/r/7/

llvm-svn: 155916
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 44521a1..4835752 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -645,7 +645,7 @@
     return false;
   }
 
-  if (C.getArgs().hasArg(options::OPT__help) ||
+  if (C.getArgs().hasArg(options::OPT_help) ||
       C.getArgs().hasArg(options::OPT__help_hidden)) {
     PrintHelp(C.getArgs().hasArg(options::OPT__help_hidden));
     return false;