Fix *-qualification of named parameters in SQL-language functions.

Given a composite-type parameter named x, "$1.*" worked fine, but "x.*"
not so much.  This has been broken since named parameter references were
added in commit 9bff0780cf5be2193a5bad0d3df2dbe143085264, so patch back
to 9.2.  Per bug #9085 from Hardy Falk.