RFR: 8262396: Update Mesa 3-D Headers to version 21.0.3

[Phil Race]

On Wed, 5 May 2021 13:45:39 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

> Update OpenGL headers to latest versions from Mesa project. I ran a sanity test on all three platforms. I also checked the diffs against the Java2D patch in openjdk/jdk#3854 and they match, excluding the Java2D-specific ifdefs.

Looks good. I also checked against the 2D version.
This may be as close as it gets to reviewing your own changes :-)

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

Marked as reviewed by prr (Reviewer).

PR: https://git.openjdk.java.net/jfx/pull/486