RFR: JDK-8312525: New test runtime/os/TestTrimNative.java#trimNative is failing: did not see the expected RSS reduction

Wed Jul 26 05:46:00 UTC 2023

The test causes intermittent rare errors, so far only seen on Oracle 7.9 with glibc 2.17.  

This PR disables, for automated testing, the RSS evaluation part of the test. It retains the mechanical part (testing whether trims happen at all, in the expected number). The stricter variant of the test is kept as manual tests (usable with jtreg without -a).

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

Commit messages:
 - change test to scan RSS only on manual mode
 - count rss reductions outside of trims too

Changes: https://git.openjdk.org/jdk/pull/14984/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14984&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8312525
  Stats: 63 lines in 5 files changed: 49 ins; 2 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/14984.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14984/head:pull/14984

PR: https://git.openjdk.org/jdk/pull/14984