RFR: 8022476: cleanup some raw types and unchecked warnings in java.util.stream

[Mike Duigou]

Hello all;

A changeset of primarily warning suppression in java.util.stream that reduces the warnings on some of the stream pipeline and ops classes.

http://cr.openjdk.java.net/~mduigou/JDK-8022476/0/webrev/

Mike