mesa: add GL_EXT_texture_border_clamp support

This extension is identical to GL_OES_texture_border_clamp. But dEQP has
tests that want the EXT variant.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
3 files changed