Use klee-libc for this test, as it runs when configured w/o uclibc.

 - If this is a problem for some reason, lets either fix the problem or move it
   into Runtime tests.
[Core] Remove support for "--use-asm-addresses".

 - I suspect no one is using this feature, and I'm not sure it is well conceived
   either. Ripping it out for now in lieu of bothering to maintain it.