The CPUID code will call kvm_arch_get_supported_cpuid() and, even though
it is undef kvm_enabled() so it never runs for user-mode emulators,
sometimes clang will not optimize it out at -O0.
That could be considered a compiler bug, however at -O0 we give it
a pass and just add the stubs.
Reported-by: Kamil Rytarowski <n54@gmx.com>
Tested-by: Kamil Rytarowski <n54@gmx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>