[foreign-memaccess+abi] RFR: 8264763: Add support for extended map modes in mapped segments

[Maurizio Cimadamore]

This simple fix add support for mapping segments using the extended map modes added by JEP 352.

I tried testing the support but, to do that properly you need specific setup (as described in JEP 352).

Anyway, I have been able to verify that now there's no exception in the memory segment code,
the failure I get is deep into the native map0 method, which throws "operation not supported", presumably because the file I'm mapping is not from NVM device.

Any extra help in testing this would be appreciated.

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Commit messages:
 - Add support for missing modes

Changes: https://git.openjdk.java.net/panama-foreign/pull/489/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=489&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8264763
  Stats: 9 lines in 2 files changed: 6 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/489.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/489/head:pull/489

PR: https://git.openjdk.java.net/panama-foreign/pull/489