hg: jdk/client: 8232154: Update Mesa 3-D Headers to version 19.2.1

[philip.race at oracle.com]

Changeset: f4270450976b
Author:    prr
Date:      2019-10-30 13:47 -0700
URL:       https://hg.openjdk.java.net/jdk/client/rev/f4270450976b

8232154: Update Mesa 3-D Headers to version 19.2.1
Reviewed-by: serb, kcr

! src/java.desktop/share/legal/mesa3d.md
- src/java.desktop/share/legal/opengl.md
! src/java.desktop/share/native/common/java2d/opengl/J2D_GL/gl.h
! src/java.desktop/share/native/common/java2d/opengl/J2D_GL/glext.h
+ src/java.desktop/share/native/common/java2d/opengl/J2D_GL/khrplatform.h
! src/java.desktop/unix/native/common/java2d/opengl/J2D_GL/glx.h
! src/java.desktop/unix/native/common/java2d/opengl/J2D_GL/glxext.h
! src/java.desktop/windows/native/libawt/java2d/opengl/J2D_GL/wglext.h