hg: jdk/jdk: 8225229: Shenandoah: trim down default number of GC threads

[shade at redhat.com]

Changeset: cfd1e298ca33
Author:    shade
Date:      2019-06-05 09:23 +0200
URL:       http://hg.openjdk.java.net/jdk/jdk/rev/cfd1e298ca33

8225229: Shenandoah: trim down default number of GC threads
Reviewed-by: rkennke

! src/hotspot/share/gc/shenandoah/shenandoahArguments.cpp
+ test/hotspot/jtreg/gc/shenandoah/options/TestThreadCounts.java