RFR: Merge jdk

[Mikael Vidstedt]

Merge in jdk-15+31

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

Commit messages:
 - Merge jdk
 - 8249018: clean up FileInstaller $test.src $cwd in vmTestbase_vm_mlvm tests
 - 8246806: Incorrect copyright header in KeyAgreementTest.java, GroupName.java
 - 8248845: AArch64: stack corruption after spilling vector register
 - 8248112: array index out of bound in FileMapInfo::check_paths
 - 8248570: Incorrect copyright header in TestUnsafeUnalignedSwap.java
 - 8208243: vmTestbase/gc/lock/jni/jnilock002/TestDescription.java fails in jdk/hs nightly
 - 8248505: Unexpected NoSuchAlgorithmException when using secure random impl from BCFIPS provider
 - 8248794: Transition JFR Periodic Task Thread to "_thread_in_native" before invoking performance counters
 - 8248219: aarch64: missing memory barrier in fast_storefield and fast_accessfield
 - ... and 98 more: https://git.openjdk.java.net/portola/compare/606a9af2...4dd827c3

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - jdk15: https://webrevs.openjdk.java.net/portola/7/webrev.00.0
 - jdk: https://webrevs.openjdk.java.net/portola/7/webrev.00.1

Changes: https://git.openjdk.java.net/portola/pull/7/files
  Stats: 11668 lines in 356 files changed: 7137 ins; 3490 del; 1041 mod
  Patch: https://git.openjdk.java.net/portola/pull/7.diff
  Fetch: git fetch https://git.openjdk.java.net/portola pull/7/head:pull/7

PR: https://git.openjdk.java.net/portola/pull/7