Concerns about dlclose() behaviour

[Brad Conroy <technosaurus@yahoo.com>]

I recently checked out the netsurf-framebuffer package from debian
and was bothered that all of the backends were compiled in...
thus requiring a bunch of extra dependencies and increasing footprint.

I am currently patching it to make the backends modular, but ran into
a concern about musl compatibility.

libnsfb is set up in such a way that each backend has (static) functions
exported in a single struct.  With normal dlclose() functionality, I could
use dlopen to get a module and run its init function, then if it fails, just
dlclose() it and try the next backend (all using the same variable and
function names, thus simplifying the implementation)

I am thinking this will still work on musl in a way similar to using
LD_PRELOAD, but wanted to verify before moving forward since many
nsfb users also use musl.

R,
Brad Conroy