Create two buckets for allocating NODE structs

This commit adds two buckets for allocating NODE structs, then allocates
"markable" NODE objects from one bucket.  The reason to do this is so
when the AST mark function scans nodes for VALUE objects to mark, we
only scan NODE objects that we know to reference VALUE objects.  If we
*did not* divide the objects, then the mark function spends too much
time scanning objects that don't contain any references.

0 files changed, 0 insertions, 0 deletions