x86_emulate: properly do IP updates and other side effects on success

x86_emulate: properly do IP updates and other side effects on success

The two MMX/SSE/AVX code blocks failed to update IP properly, and these
as well as get_reg_refix(), which "manually" updated IP so far, failed
to do the TF and RF processing needed at the end of successfully
emulated instructions.

Fix the test utility at once to check IP is properly getting updated,
and while at it macroize the respective code quite a bit, hopefully
making it easier to add further tests when the need arises.

Reported-by: Andrei LUTAS <vlutas@bitdefender.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Andrew Cooper <andrew.cooper@citrix.com>