RFR(XS): 8170470: superword may miss reductions

[Roland Westrelin]

> No. It has to be sponsored to run pre-integration testing and using JPRT.

Sorry for the confusion: I understand that I can't push it myself but
was wondering if it was too late for jdk9. Given this is a bug fix, I
guess it's good to go. Anyone to sponsor that change (I'll send a ready
to push changeset to the taker)?

Roland.