RFR: 8333653: Remove MallocHeader::get_stack

[Johan Sjölen]

Hi,

A small and trivial enhancement, I think. Today, MallocHeader knows about the `MallocSiteTable` and vice versa. That seems a bit strange to me, as it is just a data carrier. Just have only MallocSiteTable be aware of MallocHeader by deleting a method from MallocHeader.

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

Commit messages:
 - Make MallocHeader unaware of MallocSiteTable

Changes: https://git.openjdk.org/jdk/pull/19562/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19562&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333653
  Stats: 8 lines in 4 files changed: 0 ins; 5 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/19562.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19562/head:pull/19562

PR: https://git.openjdk.org/jdk/pull/19562