[8u20] Request for approval: java.time fixes 8046416 and 8046707

[roger riggs]

Please approve these two backports of java.time issues from JDK 9 to jdk 
8u20.
Both changesets applied without changes and passed the tests (old and new).

8046416: Unable to parse an Instant from fields
Changeset from JDK 9: 
http://hg.openjdk.java.net/jdk9/dev/jdk/rev/fc467102b0b2

8046707: Performance of java.time could be better
Changeset from JDK 9: 
http://hg.openjdk.java.net/jdk9/dev/jdk/rev/99d16469a830

Thanks, Roger