[jdk11u-dev] RFR: 8253048: AArch64: When CallLeaf, no need to preserve callee-saved registers in caller

[Dmitry Chuyko]

This small patch reduces registers spilling on aarch64. Changes bring the save policy in line with AArch64 ABI.

Original patch require simple adjustments to the context.

Testing: tier1, tier2, opto assembly check.

11u RFR: https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2021-May/006239.html
https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2021-May/006373.html

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Commit messages:
 - [PATCH] Backport ba174af3446b667a342947a259b45a09ff135a05

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/24/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=24&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253048
  Stats: 22 lines in 2 files changed: 0 ins; 0 del; 22 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/24.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/24/head:pull/24

PR: https://git.openjdk.java.net/jdk11u-dev/pull/24