Careful debugging of the memory leak problem. At this stage,

stack frames for interpreted (but not primitive) functions appear not to be being
reclaimed, and the oblist doesn't seem to be being fully reclaimed.

src/memory/consspaceobject.h

@@ -312,6 +312,11 @@
  */
 #define exceptionp(conspoint) (check_tag(conspoint,EXCEPTIONTV))
 
+/**
+ * true if `conspoint` points to an unassigned cell, else false
+ */
+#define freep(conspoint) (check_tag(conspoint,FREETV))
+
 /**
  * true if `conspoint` points to a function cell, else false
  */