Postgres 7.3.5 and count('x')

Hello,

It appears that the count('x') will no longer work without a type
cast.  Is this on purpose?  I've already modified my code to use
count(*) instead, but I decided to mention it anyway.

warehouse=# select count('x') ;
ERROR:  cannot accept a value of type any
warehouse=# select count('x'::text) ;count
-------    1
(1 row)