Integrated: Merge jdk18

[Jesper Wilhelmsson]

Forwardport JDK 18 -> JDK 19

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Commit messages:
 - Merge
 - 8274679: Remove unnecessary conversion to String in security code in java.base
 - 8142362: Lots of code duplication in Copy class
 - 8218857: Confusing overloads for os::open
 - 8183227: read/write APIs in class os shall return ssize_t
 - 8279300: [arm32] SIGILL when running GetObjectSizeIntrinsicsTest
 - 8278329: some TraceDeoptimization code not included in PRODUCT build
 - 8279523: Parallel: Remove unnecessary PSScavenge::_to_space_top_before_gc
 - 8279522: Serial: Remove unused Generation::clear_remembered_set
 - 8279528: Unused TypeEnter.diag after JDK-8205187
 - ... and 163 more: https://git.openjdk.java.net/jdk/compare/40df5df9...6ff1c607

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.java.net/jdk/pull/7017/files
  Stats: 27994 lines in 750 files changed: 20678 ins; 5315 del; 2001 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7017.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7017/head:pull/7017

PR: https://git.openjdk.java.net/jdk/pull/7017