tcg: make CPUClass.cpu_exec_* optional

This will let us simplify the code that initializes CPU class
methods, when we move cpu_exec_*() to a separate struct.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20201212155530.23098-11-cfontana@suse.de>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
1 file changed