High bits in the immediate operand of SSE comparisons are ignored, they
do not result in an undefined opcode exception.  This is mentioned
explicitly in the Intel documentation.

Reported-by:  <sonicadvance1@gmail.com>
Closes: https://gitlab.com/qemu-project/qemu/-/issues/184


Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>