RFR: Merge jdk18 [v2]

[Jesper Wilhelmsson]

> Forwardport JDK 18 -> JDK 19

Jesper Wilhelmsson has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 29 additional commits since the last revision:

 - Merge
 - 8278275: Initial nroff manpage generation for JDK 19
   
   Reviewed-by: erikj, jjg, iris
 - 8278630: ProblemList compiler/vectorapi/reshape/TestVectorCastAVX512.java on X64
   
   Reviewed-by: psandoz
 - 8269556: sun/tools/jhsdb/JShellHeapDumpTest.java fails with RuntimeException 'JShellToolProvider' missing from stdout/stderr
   
   Reviewed-by: kevinw, sspitsyn, amenkov
 - 8259610: VectorReshapeTests are not effective due to failing to intrinsify "VectorSupport.convert"
   
   Reviewed-by: psandoz, chagedorn
 - 8276241: JVM does not flag constant class entries ending in '/'
   
   Reviewed-by: dholmes, lfoltan
 - 8277481: Obsolete seldom used CDS flags
   
   Reviewed-by: iklam, ccheung, dholmes
 - 8271079: JavaFileObject#toUri and multi-release jars
   
   Reviewed-by: jjg, lancea, alanb
 - 8278482: G1: Improve HeapRegion::block_is_obj
   
   Reviewed-by: sjohanss, tschatzl, mli
 - 8278344: sun/security/pkcs12/KeytoolOpensslInteropTest.java test fails because of different openssl output
   
   Reviewed-by: mdoerr, goetz, stuefe
 - ... and 19 more: https://git.openjdk.java.net/jdk/compare/9d2883a1...dc02f07e

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6824/files
  - new: https://git.openjdk.java.net/jdk/pull/6824/files/dc02f07e..dc02f07e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6824&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6824&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6824.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6824/head:pull/6824

PR: https://git.openjdk.java.net/jdk/pull/6824