[jdk11u-dev] RFR: 8253638: Cleanup os::reserve_memory and remove MAP_FIXED [v2]

[Vladimir Kempik]

> Hello, please review this backport of JDK-8253638  to jdk11u-dev, its a prerequest for JDK-8255254 ( and MAP_JIT support as well) which is mac-aarch64 backport prerequest

Vladimir Kempik has updated the pull request incrementally with one additional commit since the last revision:

  Fix up windows

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

Changes:
  - all: https://git.openjdk.java.net/jdk11u-dev/pull/574/files
  - new: https://git.openjdk.java.net/jdk11u-dev/pull/574/files/8e689af9..a2bd99c1

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=574&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=574&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/574.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/574/head:pull/574

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