[jdk19u] RFR: 8296970: Remove sysThreadAvailableStackWithSlack from hotspot-symbols

[Man Cao]

Backport of https://bugs.openjdk.org/browse/JDK-8296970.

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

Commit messages:
 - Backport f662a060463c2982da40307a53d59e514390f60c

Changes: https://git.openjdk.org/jdk19u/pull/68/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19u&pr=68&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296970
  Stats: 4 lines in 2 files changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk19u/pull/68.diff
  Fetch: git fetch https://git.openjdk.org/jdk19u pull/68/head:pull/68

PR: https://git.openjdk.org/jdk19u/pull/68