hg: jdk/sandbox: 8205461: Create Collector which merges results of two other collectors

[chris.hegarty at oracle.com]

Changeset: 490d9001eba9
Author:    plevart
Date:      2018-09-25 14:23 +0200
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/490d9001eba9

8205461: Create Collector which merges results of two other collectors
Reviewed-by: briangoetz, smarks, plevart
Contributed-by: amaembo at gmail.com

! src/java.base/share/classes/java/util/stream/Collectors.java
! test/jdk/java/util/stream/test/org/openjdk/tests/java/util/stream/CollectorsTest.java