RFR: 8347302: Update ProcessTools.java to support virtual test factory for Xbootclasspath/a:

[Leonid Mesnik]

Test
runtime/cds/appcds/jigsaw/modulepath/OptimizeModuleHandlingTest.java
uses
-Xbootclasspath/a: classpath
(2 arguments)

Such usage of options -Xbootclasspath/a: should be correctly processed by virtual thread factory support in ProcessTools.

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

Commit messages:
 - 8347304: Update ProcessTools.java to support virtual test factory for Xbootclasspath/a:

Changes: https://git.openjdk.org/jdk/pull/22993/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22993&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347302
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22993.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22993/head:pull/22993

PR: https://git.openjdk.org/jdk/pull/22993