TestPromotionEventWithG1.java failed due to "RuntimeException: PLAB size is smaller than object size."

The following test failed due to an exception on Linux-X64
in a fastdebug and a slowdebug config using jdk-12+16 bits:

jdk/jfr/event/gc/detailed/TestPromotionEventWithG1.java

The test only failed in 1 of 3 'fastdebug' bits runs and 1 of 3
'slowdebug' bits runs so I'm tagging this bug as intermittent.
It did not fail at all in the 'release' bits runs.

Here's a snippet from one of the log files:

----------System.out:(0/0)----------
----------System.err:(65/2436)----------
java.lang.RuntimeException: PLAB size is smaller than object size. Event: PromoteObjectInNewPLAB {
  startTime = 21955328706
  eventThread = {
    osName = "GC Thread#2"
    osThreadId = 24965
    javaName = null
    javaThreadId = 0
    group = null
  }
  gcId = 36
  objectClass = {
    classLoader = {
      type = null
      name = "bootstrap"
    }
    name = "[B"
    package = null
    modifiers = 0
  }
  objectSize = 144
  tenuringAge = 1
  tenured = true
  plabSize = 24
}
: expected true, was false
        at jdk.test.lib.Asserts.fail(Asserts.java:594)
        at jdk.test.lib.Asserts.assertTrue(Asserts.java:486)
        at jdk.jfr.event.gc.detailed.PromotionEvent.verifyPromotionSampleEvents(PromotionEvent.java:173)
        at jdk.jfr.event.gc.detailed.PromotionEvent.test(PromotionEvent.java:140)
        at jdk.jfr.event.gc.detailed.TestPromotionEventWithG1.main(TestPromotionEventWithG1.java:42)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
        at java.base/java.lang.Thread.run(Thread.java:835)

JavaTest Message: Test threw exception: java.lang.RuntimeException: PLAB size is smaller than object size. Event: PromoteObjectInNewPLAB {
  startTime = 21955328706
  eventThread = {
    osName = "GC Thread#2"
    osThreadId = 24965
    javaName = null
    javaThreadId = 0
    group = null
  }
  gcId = 36
  objectClass = {
    classLoader = {
      type = null
      name = "bootstrap"
    }
    name = "[B"
    package = null
    modifiers = 0
  }
  objectSize = 144
  tenuringAge = 1
  tenured = true
  plabSize = 24
}
: expected true, was false
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: PLAB size is smaller than object size. Event: PromoteObjectInNewPLAB { startTime = 21955328706 eventThread = { osName = "GC Thread#2" osThreadId = 24965 javaName = null javaThreadId = 0 group = null } gcId = 36 objectClass = { classLoader = { type = null name = "bootstrap" } name = "[B" package = null modifiers = 0 } objectSize = 144 tenuringAge = 1 tenured = true plabSize = 24 } : expected true, was false
----------rerun:(40/4410)*----------