RFR: 8369263: Parallel: Inline PSPromotionManager::push_depth

[Albert Mingkun Yang]

Trivial inlining a method to its single caller.

Test: tier1

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Commit messages:
 - pgc-trivial

Changes: https://git.openjdk.org/jdk/pull/27668/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27668&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8369263
  Stats: 7 lines in 2 files changed: 0 ins; 6 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27668.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27668/head:pull/27668

PR: https://git.openjdk.org/jdk/pull/27668