The jtreg test for the jcmd "GC.heap_info" is currently limited in that it doesn't check for any substantial information when checking the output of the command. JDK-8356848 improved the test marginally by checking for the "used" string, which is common among all GCs. Since each GC have a unique approach to printing the heap, the test requires a different approach. A good starting point might be to take inspiration from the hsdb test serviceability/sa/TestUniverse.java.

The affected test:
test/hotspot/jtreg/serviceability/dcmd/gc/HeapInfoTest.java