RFR: 8232210: Update Mesa 3-D Headers to version 19.2.1

[Kevin Rushforth]

On Tue, 29 Oct 2019 23:05:44 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

> This PR updates the header files we use the build the OpenGL ES2 pipeline to Mesa 19.2.1. See [this review thread](https://mail.openjdk.java.net/pipermail/2d-dev/2019-October/010372.html) for the equivalent change that is under review for Java2D.
> 
> The updates to the `gl.h` and `glx.h` files are large, since we are many, many years behind.
> 
> The `*ext.h` header files were updated fairly recently, so those diffs are not large.
> 
> Previously we used to get the `*ext.h` headers from Khronos, but now we get all the headers from the Mesa project.
> 
> This reduces the number of upstream sources we need to monitor.
> 
> I note that with this update, the `glxext.h` and `wglext.h` files are slightly older in the Mesa bundle than in Khronos, but the differences are not relevant to FX.
> 
> I did a full build and test on Mac and Linux and a sanity build (with `-PINCLUDE_ES2=true`) on Windows. I also verified that the build artifacts are unchanged.
> 
> As with the Java2D change, the licensing terms are the same as before, but since we no longer get files directly from Khronos, the `opengl_fx.md` file is gone and the `mesa3d.md` is updated as required to mention these files.
> 
> ----------------
> 
> Commits:
>  - 7a520adc: 8232210: Update Mesa 3-D Headers to version 19.2.1
> 
> Changes: https://git.openjdk.java.net/jfx/pull/26/files
>  Webrev: https://webrevs.openjdk.java.net/jfx/26/webrev.00
>   Issue: https://bugs.openjdk.java.net/browse/JDK-8232210
>   Stats: 1515 lines in 8 files changed: 1076 ins; 269 del; 170 mod
>   Patch: https://git.openjdk.java.net/jfx/pull/26.diff
>   Fetch: git fetch https://git.openjdk.java.net/jfx pull/26/head:pull/26

Reviewers: @prrace, @arapte, @johanvos

PR: https://git.openjdk.java.net/jfx/pull/26