RFR: 8349254: Disable "best-fit" mapping on Windows environment variables

[Naoto Sato]

This is a follow-on fix to [JDK-8337506](https://bugs.openjdk.org/browse/JDK-8337506). The Java launcher can take arguments from "JDK_JAVA_OPTIONS" environment variable, so the same processing is needed. Also, obsolete code for Windows 9x has been removed.

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Commit messages:
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/23498/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23498&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349254
  Stats: 137 lines in 3 files changed: 68 ins; 45 del; 24 mod
  Patch: https://git.openjdk.org/jdk/pull/23498.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23498/head:pull/23498

PR: https://git.openjdk.org/jdk/pull/23498