RFR: 8318102: macos10.14 check in CSystemColors can be removed.

[Prasanta Sadhukhan]

Since [ JDK-8317970](https://bugs.openjdk.org/browse/JDK-8317970) in integrated to make macOS 11 the minimum version to build jdk, the 10.14 check added in [JDK-8284166](https://bugs.openjdk.org/browse/JDK-8284166) is not needed and can be removed..

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Commit messages:
 - 8318102: macos10.14 check in CSystemColors can be removed.
 - Merge remote-tracking branch 'upstream/master'
 - Merge remote-tracking branch 'upstream/master'
 - Revert "Fix"
 - Fix

Changes: https://git.openjdk.org/jdk/pull/16198/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16198&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318102
  Stats: 10 lines in 1 file changed: 0 ins; 8 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/16198.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16198/head:pull/16198

PR: https://git.openjdk.org/jdk/pull/16198