Numbers boxed by dyn expressions and the leaves of parsed documents are
most of the checked-dynamic churn. They own no dyn edges, are never cycle
candidates or weak keys, and never acquire a prototype or symbol table, so
their last release pushes them straight onto the misc pool and allocation
pops them with a minimal reset. Generic disposal now also clears the
released prototype, so every pooled node has NULL prototype and symbol
tables.
Malte Ubl
7fb5e17713