to be used in re-entrant (=multithreaded) code
Icky things: the _r API is not standardized and
the _r-forms require per-thread data to store their state
- memory profiler: turn malloc.c:Perl_get_mstats() into
- an extension (Devel::MProf?) that would return the malloc
- stats in a nice Perl datastructure (also a simple interface
- to return just the grand total would be good)
cross-compilation support
host vs target: compile in the host, get the executable to
the target, get the possible input files to the target,