I don't see anything there that would cause your problem. Maybe you are attempting to link to the test_support.o module multiple times? This can be verified if you post the complete output from your compiler.
As an unrelated note, you are including stdlib twice (once as cstdlib, and once as stdlib.h). You should get rid of the stdlib.h and change stdio.h to cstdio.
Sorry everyone. Turned out I had some funky stuff in my Makefile. It was stuff that other people in this lab made, and I didnt know enough about Makefiles to know that it was causing a problem.
Thanks for your patience with me though!