[plt-scheme] ffi: dlopen in unix

> RTLD_GLOBAL is not used when you pass in #f -- this passes NULL to
> dlopen, and no linking of new names is done.
RTLD_GLOBAL is always used, #f passes in NULL for the name argument but
I was saying maybe only RTLD_GLOBAL is needed when the name is NULL( #f
). Perhaps this is not the case as you say below.
>   OTOH, there are cases
> where RTLD_GLOBAL is needed, when one library requires loading another
> library in and wants to use its `bindings' (at least this is my
> understanding of these things).  Maybe an optional argument should be
> added to ffi-lib at some point?
>   
How about just a 3rd parameter to ffi-lib, 'global or 'local which would
correspond directly to RTLD_GLOBAL or RTLD_LOCAL?