closure regression

[alandipert]

As of 4cc3a85, the following programs error:

((fn () 123))
;; expected 123

(def F (fn (x) (fn () x)))
((F 1)) 
;; expected 1

[quoll]

The array code was testing param seqs as either arrays or lists, but was not testing for nil. Nil is an honorary list, but the type returned is "symbol", not "cons".

The same mistake was made in 2 places. This is a good example of why I was concerned about the "if" blocks around arrays vs cons-lists. Looking forward to dispatching on type.