Test R+ponant+mfence+WB+UC

X86_64 R+ponant+mfence+WB+UC
"PodWWNaNT CoeNTNa MFencedWR Fre"
MT=x:WB y:UC
Generator=diyone7 (version 7.56+02~dev)
Prefetch=0:x=F,0:y=W,1:y=F,1:x=T
Com=Co Fr
Orig=PodWWNaNT CoeNTNa MFencedWR Fre
Align=
{
0:rax=y;
}
 P0                  | P1            ;
 movl $1,(x)         | movl $2,(y)   ;
 movl $1,%ebx        | mfence        ;
 movntil %ebx,(%rax) | movl (x),%eax ;
exists (y=2 /\ 1:rax=0)