Original fix for JDK-8299426 (Heap dump does not contain virtual Thread stack
references, #16665) caused failures of new test (added while #16665 was under
review):
test/hotspot/jtreg/compiler/c2/TestReduceAllocationAndHeapDump.java in many
tears and was reverted.
Segmented heap dump assumes "merge" stage is executed outside of safepoint (to
not block the VM), but heap dump may happen during safepoint (and
TestReduceAllocationAndHeapDump.java test provoke the case).
The change contains original fix for JDK-8299426 ("[original
fix](https://github.com/openjdk/jdk/commit/bdbf768eafa86e0007aca4188e0567693afe9071)")
and removes asserts from HeapMerger ([allow heapdump in
safepoints](https://github.com/openjdk/jdk/commit/44670ca4bf55dd2a5f1f44686758844aed68937e)).
Run tier1-3 and heapdump-related tests.
-------------
Commit messages:
- allow heapdump in safepoints
- original fix
Changes: https://git.openjdk.org/jdk/pull/17040/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17040&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8321565
Stats: 319 lines in 3 files changed: 152 ins; 81 del; 86 mod
Patch: https://git.openjdk.org/jdk/pull/17040.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/17040/head:pull/17040
PR: https://git.openjdk.org/jdk/pull/17040
