Currently -nodefconfig doesn't disable import of cpu-x86_64.conf.
This combined with -readconfig imports occurring after cpudef_setup()
disallow pointing qemu at an alternate cpu-x86_64.conf file.
User effectively can't read in alternate cpu-x86_64.conf file impacting
qemu debug and potentially end user local configuration.
Requires moving/overwriting default config files by the user.
-nodefconfig works as intended and intuitively expected.