RFR: 8260931: Implement JEP 382: New macOS Rendering Pipeline [v5]

[Ajit Ghaisas]

> **Description :**
> This is the implementation of [JEP 382 : New macOS Rendering Pipeline](https://bugs.openjdk.java.net/browse/JDK-8238361)
> It implements a Java 2D internal rendering pipeline for macOS using the Apple Metal API.
> The entire work on this was done under [OpenJDK Project - Lanai](http://openjdk.java.net/projects/lanai/)
> 
> We iterated through several Early Access (EA) builds and have reached a stage where it is ready to be integrated to openjdk/jdk. The latest EA build is available at - https://jdk.java.net/lanai/
> 
> A new option -Dsun.java2d.metal=true | True needs to be used to use this pipeline.
> 
> **Testing :**
> This implementation has been tested with the tests present at - [Test Plan for JEP 382: New macOS Rendering Pipeline](https://bugs.openjdk.java.net/browse/JDK-8251396)
> 
> **Note to reviewers :**
> 1) Default rendering pipeline on macOS has not been changed by this PR. OpenGL still stays as the default rendering pipeline and Metal rendering pipeline is optional to choose.
> 
> 2) To apply and test this PR - 
> To enable the metal pipeline you must specify on command line -Dsun.java2d.metal=true (No message will be printed in this case) or -Dsun.java2d.metal=True (A message indicating Metal rendering pipeline is enabled gets printed)
> 
> 3) Review comments (including some preliminary informal review comments) are tracked with JBS issues - https://bugs.openjdk.java.net/issues/?filter=40598

Ajit Ghaisas has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - Merge branch 'master' into 8260931_lanai_JEP_branch
   Merge
 - Lanai PR#177 - 8261430 - aghaisas
 - Lanai PR#176 - 8261399 - jdv
 - Lanai PR#175 - 8261304 - aghaisas
 - Lanai PR#174 - 8261234 - kcr
 - Merge branch 'master' into 8260931_lanai_JEP_branch
   Merge from openjdk/jdk
 - Project Lanai Patch

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2403/files
  - new: https://git.openjdk.java.net/jdk/pull/2403/files/64173289..9a72538a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2403&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2403&range=03-04

  Stats: 6660 lines in 320 files changed: 3899 ins; 1099 del; 1662 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2403.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2403/head:pull/2403

PR: https://git.openjdk.java.net/jdk/pull/2403