[jdk11u-dev] RFR: 8250597: G1: Improve inlining around trim_queue

[Dmitry Chuyko]

This change improves latency with G1 in some cases and makes trim_queue() code structure closer to current mainline.

The original patch does not apply cleanly in particular because of https://bugs.openjdk.java.net/browse/JDK-8200545 . However the refactoring is rather simple because it is a rearrangement of code between functions with compiler hints. It has been reproduced (short description in the next comment).

The change is isolated and is a set of code moves so the risk is low.

Testing: tier1, tier2 on aarch64 and x86_64 in development, the change has been included in Liberica JDK 11u EA for some time.

As an example of performance improvement, Critical-jOPS on Graviton2 raised +1%:+6.2% for 8GB heap.

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Commit messages:
 - [PATCH] Backport e648a907b31fd0d6b746d149fda2a8d5fbe26dc0

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/26/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=26&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8250597
  Stats: 373 lines in 5 files changed: 196 ins; 153 del; 24 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/26.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/26/head:pull/26

PR: https://git.openjdk.java.net/jdk11u-dev/pull/26