Test ppc-iwp2.6

PPC ppc-iwp2.6 (PPCiwpTwoSix)
"Checks write serialization"
{
 P0:r5 = 55; P1:r6 = 66; x = 0;
 P0:r1 = x; P1:r1 = x; P2:r1 = x; P3:r1 = x
};

    P0      |    P1       |    P2       |      P3     ;
stw r5,0,r1 | stw r6,0,r1 | lwz r5,0,r1 | lwz r5,0,r1 ;
            |             | lwz r6,0,r1 | lwz r6,0,r1 ;

Observed
    2:r5=0; 2:r6=55; 3:r5=66; 3:r6=55;
and 2:r5=66; 2:r6=55; 3:r5=0; 3:r6=66;
and 2:r5=0; 2:r6=55; 3:r5=55; 3:r6=66;
and 2:r5=0; 2:r6=66; 3:r5=55; 3:r6=66;
<<
genprog generated/ppc-iwp2.6-prog.tex
show 0
essdump generated/ppc-iwp2.6-ess.dot
>>
<<
show 0 of ess 0
readfrom generated/ppc-iwp2.6-rf.dot
>>