RFR: 8270096: Shenandoah: Optimize gc/shenandoah/TestRefprocSanity.java for interpreter mode

[Aleksey Shipilev]

Found this while testing Shenandoah with Zero. This configuration takes a lot of time, and eventually times out:


$ time CONF=linux-x86_64-server-fastdebug make run-test TEST=gc/shenandoah/TestRefprocSanity.java TEST_OPTS="JAVA_OPTIONS=-Xint"
<timeout after 1200 seconds>


With these fixes, the run time with `-Xint` is under 1 minute:


real	0m51.472s
user	3m0.366s
sys	0m5.473s


In default mode, the run time is now under 20 seconds:


real	0m20.584s
user	1m8.693s
sys	0m5.030s


This also passes with Zero (plus some Zero fixes) now.

-------------

Commit messages:
 - Drop the window to 1K too
 - 8270096: Shenandoah: Optimize gc/shenandoah/TestRefprocSanity.java for interpreter mode

Changes: https://git.openjdk.java.net/jdk/pull/4725/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4725&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8270096
  Stats: 17 lines in 1 file changed: 7 ins; 0 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4725.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4725/head:pull/4725

PR: https://git.openjdk.java.net/jdk/pull/4725