Let memory sizes of the various IMEMO object types be reflected correctly

[methodmissing]

Supersedes #2112. In current trunk only the imemo_tmpbuf type's auxiliary malloc heap buffer is factored into obj_memsize_of. The following IMEMO types also allocate on the malloc heap:

• imemo_env (similar pattern as imemo_tmpbuf, an array of VALUEs)
• imemo_ment (single struct allocated)
• imemo_iseq (massaged the iseq_memsize API a little)
• imemo_ast (more difficult to get right, need to walk buffer elements too)

The imemo_memsize function introduced attempts to be the entry point for object size calculation of the IMEMO types.

[ko1]

Just curious. How to use them?