[lworld] RFR: 8271959: [lworld] Convert Optional and VBS classes to value class [v3]

[Roger Riggs]

> Make copies of classes to be made value classes in src/java.base/valueclasses/classes 
> Modify CompileJavaModules.gmk to trigger builds of values classes and construct a .jar for each module.
> Add the jar files to $JAVA_HOME/lib/valueclasses/<module\>-valueclasses.jar 
> 
> Modify hotspot arguments.cpp to scan for patch jar files when --enable-preview and -XX:+EnableValhalla.
> For each jar, the equivalent of --patch-module <module>=<path-to-jar> is added and the system properties `jdk.module.patch.<n>` include jar file paths.

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  Replaced patch_mod_javabase with a check for an empty list of --patch-modules.
  Other review comment cleanup.

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/816/files
  - new: https://git.openjdk.org/valhalla/pull/816/files/15b8caf0..f7eb632f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=816&range=02
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=816&range=01-02

  Stats: 23 lines in 2 files changed: 0 ins; 2 del; 21 mod
  Patch: https://git.openjdk.org/valhalla/pull/816.diff
  Fetch: git fetch https://git.openjdk.org/valhalla pull/816/head:pull/816

PR: https://git.openjdk.org/valhalla/pull/816