x86emul: support VPCLMULQDQ insns
As to the feature dependency adjustment, while strictly speaking AVX is
a sufficient prereq (to have YMM registers), 256-bit vectors of integers
have got fully introduced with AVX2 only. Sadly gcc can't be used as a
reference here: They don't provide any AVX512-independent built-in at
all.
Along the lines of PCLMULQDQ, since the insns here and in particular
their memory access patterns follow the usual scheme, I didn't think it
was necessary to add a contrived test specifically for them, beyond the
Disp8 scaling one.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>