[11u] RFR: 8227645: Some tests in serviceability/sa run with fixed -Xmx values and risk running out of memory

[Lindenmaier, Goetz]

Hi,

I would like to downport this for parity with 11.0.7-oracle.

This change moves tests into a new directory.

The patch does not apply clean because
test/hotspot/jtreg/serviceability/sa/ClhsdbRegionDetailsScanOopsForG1.java
lacks 
"8217473: SA: Tests using ClhsdbLauncher fail on SAP docker containers"
and
"8215568: Refactor SA clhsdb tests to use ClhsdbLauncher"
which each introduced a minor fix in the test.

Downporting these two changes will fail for this file as it was moved. 
I added the chunk of 8217473 to the test, as it's a standalone fix.
The chunk of 8215568 breaks the test, so I left it out.

Please review:
http://cr.openjdk.java.net/~goetz/wr20/8227645-SA_test_oom-jdk11/01/
https://bugs.openjdk.java.net/browse/JDK-8227645
https://hg.openjdk.java.net/jdk/jdk/rev/a64caa5269cf

Best regards,
  Goetz.