[jdk17u] RFR: 8272318: Improve performance of HeapDumpAllTest

[Aleksey Shipilev]

Clean backport to improve testing.

Additional testing: 
 - [x] Affected test still passes

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Commit messages:
 - Backport 73da66ffb707abf6dc38368a12e337d52597de25

Changes: https://git.openjdk.java.net/jdk17u/pull/61/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=61&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8272318
  Stats: 12 lines in 1 file changed: 12 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/61.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/61/head:pull/61

PR: https://git.openjdk.java.net/jdk17u/pull/61