[CM] On FFI bindings

[bil at ccrma.Stanford.EDU]

> how does C behave if you assume that the called function has a 
> signature
> of (s7_scheme* sc) and you try to pass (s7_scheme* sc, s7_pointer args) 
> ?

I tried it with the tlib example, and if you declare args in C, but
don't pass them in scheme (i.e. no init_args in the environment),
I get a segfault.  The other way (no args declared, but you pass and
use them anyway) seems to work -- strange!  This is in gcc 10.2
in Linux.