create Streamable and ParallelStreamable interface and use them in Collection and Optional
------------- Commit messages: - 8272137: no CR - 8272137: create Streamable and ParallelStreamable interface and use in Collection and Optional Changes: https://git.openjdk.java.net/jdk/pull/5050/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5050&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8272137 Stats: 104 lines in 4 files changed: 101 ins; 0 del; 3 mod Patch: https://git.openjdk.java.net/jdk/pull/5050.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/5050/head:pull/5050 PR: https://git.openjdk.java.net/jdk/pull/5050
