PATCH RFA: Avoid enum bitfield in C++ frontend

[Jason Merrill]

Ian Lance Taylor wrote:
> 2009-04-15  Ian Lance Taylor  <iant@google.com>
> 
> 	* cp-tree.h (enum tsubst_flags): Rename from enum tsubst_flags_t.
> 	(tsubst_flags_t): Change typedef from enum type to int.

OK.

Jason