I noticed this was disabled in the recent refactoring.
This patch implementation seems to return smaller sizes
than I expected, so maybe that is the result of improvements
and moving data around or likely I missed something.
Only lightly checked, I'll check again another day/week
or someone else can look at it.
iseq.c (iseq_memsize): reimplement for wrapper
(param_keyword_size): extracted from iseq_memsize
(iseqw_mark): new mark function
(iseqw_data_type): new data type
(iseqw_new): wrap as iseqw_data_type
(iseqw_check): adjust for wrapper
(Init_ISeq): remove iseqw_iseq_key initialization