[jdk16u] RFR: 8260349: Cannot programmatically retrieve Metaspace max set via JAVA_TOOL_OPTIONS

[Harold Seigel]

Backport of JDK-8260349 to JDK-16u.  The patch applied cleanly and was tested with tiers 1-2 on Linux, Windows, and Mac OS, and tiers 3-5 on Linux x64.

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Commit messages:
 - Backport b6a736738ae025604d86924298fdd04a7851b85f

Changes: https://git.openjdk.java.net/jdk16u/pull/38/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk16u&pr=38&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8260349
  Stats: 123 lines in 2 files changed: 120 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk16u/pull/38.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk16u pull/38/head:pull/38

PR: https://git.openjdk.java.net/jdk16u/pull/38