Add some tests for unusual forms of namespace export

Author: mlochbaum

test/cases/namespace.bqn

@@ -10,6 +10,8 @@
 4  % ⟨o⟩←{_o←˜⋄_o⇐}⋄+_o 2
 5  % ⟨n⟩←{_n_⇐⋄n←5}⋄n
 7  % ⟨n⟩←{N‿·⇐⋄n←7}⋄n
+2  % ⟨q⟩←{⟨[·,q]⇐ignored⟩⇐⋄q←2}⋄q
+3  % ⟨a⟩←{a←3⋄a‿a‿a⇐}⋄a
 4  % c←0⋄⟨a,b⟩←{b⇐1⋄a⇐2}⋄⟨b,c⟩↩{a‿b‿c⇐3+↕3}⋄b
 10 % r‿s←{r‿q←{q⇐1+r⇐2}⋄s⇐5⋄r⇐}⋄r×s
 !  % -´⟨a,b,c⟩←{b⇐2⋄⟨c,a⟩⇐4‿3}