AMX Mod X is compiled for "i586" CPUs on Linux already. There is no need to recompile it for anything higher.
Plugins are not OS or processor dependent, they work anywhere, so if they're failing to load it's because you compiled Core wrong (most likely your CPU did not support i586 instructions).
If AMX Mod X is not working on your CPU by default then it's possible the instruction set is too old for even that. You can post a bug report in this case.