Integrate:

Integrate:
[ 24258]
Merge common code. Reduces object size by 1K on x86, 6K on PPC

[ 24340]
The if() clause is the wrong way round, so OOK can never be true in
this case. Given that OOK is never undone, we could never have been
correctly upgrading a PV with OOK to HV or AV. I believe that only
SVt_NULL is the only type ever upgraded to HV or AV.
p4raw-link: @24340 on //depot/perl: c2bfdfaf3f7731071c0d7c0684c538dffecf7ac6
p4raw-link: @24258 on //depot/perl: bd4b1eb5b0b53616d16d03ba8f6aedf325adfa1d

p4raw-id: //depot/maint-5.8/perl@27141
p4raw-edited: from //depot/perl@24340 'edit in' sv.c (@24271..)