Currently, the Cascadelake-Server, Icelake-Client, and
Icelake-Server are always generating the following warning:

  qemu-system-x86_64: warning: \
    host doesn't support requested feature: CPUID.07H:ECX [bit 4]

This happens because OSPKE was never returned by
GET_SUPPORTED_CPUID or x86_cpu_get_supported_feature_word().
OSPKE is a runtime flag automatically set by the KVM module or by
TCG code, was always cleared by x86_cpu_filter_features(), and
was not supposed to appear on the CPU model table.

Remove the OSPKE flag from the CPU model table entries, to avoid
the bogus warning and avoid returning invalid feature data on
query-cpu-* QMP commands.  As OSPKE was always cleared by
x86_cpu_filter_features(), this won't have any guest-visible
impact.

Include a test case that should detect the problem if we introduce
a similar bug again.

Fixes: c7a88b52 ("i386: Add new model of Cascadelake-Server")
Fixes: 8a11c62d ("i386: Add new CPU model Icelake-{Server,Client}")
Cc: Tao Xu <tao3.xu@intel.com>
Cc: Robert Hoo <robert.hu@linux.intel.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190319200515.14999-1-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>