hg: jigsaw/jake/jdk: Replace use of Collections/HashSet with Set.of in SystemModuleDescriptionPlugin

[mandy.chung at oracle.com]

Changeset: c743bdb70352
Author:    redestad
Date:      2016-09-16 10:57 -0700
URL:       http://hg.openjdk.java.net/jigsaw/jake/jdk/rev/c743bdb70352

Replace use of Collections/HashSet with Set.of in SystemModuleDescriptionPlugin
Reviewed-by: alanb, mchung

! src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/SystemModuleDescriptorPlugin.java