RFR: 8297570: jdk/jfr/threading/TestDeepVirtualStackTrace.java fails with -XX:-UseTLAB

[Aleksey Shipilev]

This is the only test in `jdk_loom` that fails without `-XX:-UseTLAB`. The test specifically looks for `ObjectAllocationOutsideTLAB` event, and there are lots of those events with `-XX:-UseTLAB`. We can fix the test to look for the event we actually want.

This depends on [JDK-8297491](https://bugs.openjdk.org/browse/JDK-8297491) that fixed Loom code to actually disable TLABs.

Additional testing:
 - [x] Affected test with `-XX:+UseTLAB` and `-XX:-UseTLAB`

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

Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/11352/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11352&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297570
  Stats: 36 lines in 1 file changed: 20 ins; 2 del; 14 mod
  Patch: https://git.openjdk.org/jdk/pull/11352.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11352/head:pull/11352

PR: https://git.openjdk.org/jdk/pull/11352