[jdk11u-dev] RFR: 8255254: Split os::reserve_memory and os::map_memory_to_file interfaces

[Vladimir Kempik]

Please review this backport of JDK-8255254 to jdk11u-dev.
This is a prerequest for mac-aarch64 and MAP_JIT support
It's not applying clean due to the miss of these two patches
JDK-8253639: Change os::attempt_reserve_memory_at parameter order
JDK-8253650: Cleanup: remove alignment_hint parameter from os::reserve_memory
But they aren't critical and the patch can easily be modified

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Depends on: https://git.openjdk.java.net/jdk11u-dev/pull/574

Commit messages:
 - 8255254: Split os::reserve_memory and os::map_memory_to_file interfaces

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/578/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=578&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255254
  Stats: 168 lines in 9 files changed: 88 ins; 52 del; 28 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/578.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/578/head:pull/578

PR: https://git.openjdk.java.net/jdk11u-dev/pull/578