[lworld] RFR: Merge jdk

[David Simms]

Merge tag 'jdk-16+25'

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

Commit messages:
 - Accidentally removed java_return_convention
 - Merge tag 'jdk-16+25' into lworld_merge_jdk_16_25
 - 8255936: "parsing found no loops but there are some" assertion failure with Shenandoah
 - 8256461: AbstractFileSystemProvider.getSunPathForSocketCall for empty Path returns '.'
 - 8253081: G1 fails on stale objects in archived module graph in Open Archive regions
 - 8255368: Math.exp() gives wrong result for large values on x86 32-bit platforms
 - 8256476: Assert in vmIntrinsics::flags_for with -XX:+Verbose
 - 8256435: [TESTBUG] java/foreign/TestHandshake.java fails with direct buffer memory OOM
 - 8255448: Fastdebug JVM crashes with Vector API when PrintAssembly is turned on
 - 8134630: make code and comments consistent for stack lock optimization
 - ... and 74 more: https://git.openjdk.java.net/valhalla/compare/39c775ff...7e9e4dc1

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - lworld: https://webrevs.openjdk.java.net/?repo=valhalla&pr=272&range=00.0
 - jdk: https://webrevs.openjdk.java.net/?repo=valhalla&pr=272&range=00.1

Changes: https://git.openjdk.java.net/valhalla/pull/272/files
  Stats: 20136 lines in 466 files changed: 12280 ins; 5157 del; 2699 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/272.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/272/head:pull/272

PR: https://git.openjdk.java.net/valhalla/pull/272