[Yhc] Warning: scons fullclean recommended

[Neil Mitchell]

Hi,

Just a small warning, I would recommend people do a scons fullclean,
as I just fixed a bug that will possibly result in corrupt hbc files
(unlikely) but definately in corrupt ycr files (yhc core output).

In wrapping the Id type, deriving Show was used, which outputs "Id n",
instead of n, hence LAMBDA256 was output as LAMBDAId 256 - a valid
string, but a bit weird. I'd recommend a scons fullclean to get rid of
these oddities.

Thanks

Neil