RFR: JDK-8275703: System.loadLibrary fails on Big Sur for libraries hidden from filesystem [v2]

[Mandy Chung]

> On, macOS 11.x, system libraries are loaded from dynamic linker cache.  The libraries are no longer present on the filesystem.   `NativeLibraries::loadLibrary` checks for the file existence before calling `JVM_LoadLibrary`.   Such check no longer applies on Big Sur.   This proposes that on macOS >= 11, it will skip the file existence check and attempt to load a library for each path from java.library.path and system library path.

Mandy Chung has updated the pull request incrementally with two additional commits since the last revision:

 - Adjust parsing os.version to handle no dot version in case it's allowed
 - Exclude building exeLibraryCache.c on other platforms except macOS

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6127/files
  - new: https://git.openjdk.java.net/jdk/pull/6127/files/e034029f..710925b5

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6127&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6127&range=00-01

  Stats: 12 lines in 5 files changed: 2 ins; 3 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6127.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6127/head:pull/6127

PR: https://git.openjdk.java.net/jdk/pull/6127