RFR: 8255982: Extend BasicJMapTest to test with different GC Heap [v3]

[Aleksey Shipilev]

On Wed, 11 Nov 2020 10:48:12 GMT, Lin Zang <lzang at openjdk.org> wrote:

>> The implementation of jmap tool depends on the implementation of object iteration by different GC heap.
>> This patch extend the BasicJMapTest to cover differet GC Heap.
>
> Lin Zang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Refine the test configuration.

I think it is fine to omit Epsilon from this testing. There is another trick you can use: `@test id=serial` would name the tests appropriately, not just "id#":

Running test 'jtreg:test/jdk/sun/tools/jmap/BasicJMapTest.java'
Passed: sun/tools/jmap/BasicJMapTest.java#parallel
Passed: sun/tools/jmap/BasicJMapTest.java#serial
Passed: sun/tools/jmap/BasicJMapTest.java#z
Passed: sun/tools/jmap/BasicJMapTest.java#g1
Passed: sun/tools/jmap/BasicJMapTest.java#shenandoah
Test results: passed: 5

I also tested this patch with x86_32 that implicitly disables Z, and it passes. Also passes with TEST_VM_OPTS="-XX:+UseSerialGC", with only one config automatically selected.

@iignatev might want to ack this, as our resident test overseer.

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

Marked as reviewed by shade (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/1094