RFR: 8338626: CDS handling of JAR Class-Path attribute should allow / separator on Windows

[Calvin Cheung]

On Windows, we can use '/' as the file separator in the classpath not in the `Class-Path:` attribute.
This patch is to enable the use of '/' as the file separator in the `Class-Path:`attribute on Windows.

Passes tiers 1 - 3 testing.

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

Commit messages:
 - 8338626: CDS handling of JAR Class-Path attribute should allow / separator on Windows

Changes: https://git.openjdk.org/jdk/pull/20924/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20924&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8338626
  Stats: 41 lines in 2 files changed: 41 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20924.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20924/head:pull/20924

PR: https://git.openjdk.org/jdk/pull/20924