RFR: 8341060: Cleanup statics in HeapDumper [v2]

[Alex Menkov]

> The fix cleans up static variables/methods in HeapDumper.
> See jira for details.
> 
> Testing:
>   heap dump-related tests (test/hotspot/jtreg/serviceability, test/hotspot/jtreg/compiler/c2/TestReduceAllocationAndHeapDump.java, test/hotspot/jtreg/runtime/ErrorHandling, test/hotspot/jtreg/gc/epsilon, test/jdk/sun/tools/jhsdb, test/jdk/sun/tools/jmap, test/jdk/com/sun/management/HotSpotDiagnosticMXBean)

Alex Menkov has updated the pull request incrementally with one additional commit since the last revision:

  feedback

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/21216/files
  - new: https://git.openjdk.org/jdk/pull/21216/files/98abe42c..73d5ce69

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21216&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21216&range=00-01

  Stats: 35 lines in 1 file changed: 12 ins; 19 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/21216.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21216/head:pull/21216

PR: https://git.openjdk.org/jdk/pull/21216