features: Also check EXT_depth_clamp

This GLES extension has been merged into the OpenGL registry, so it may
now become available.

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>

src/vrend_renderer.c

@@ -176,7 +176,7 @@ static const  struct {
    FEAT(debug_cb, UNAVAIL, UNAVAIL, NULL), /* special case */
    FEAT(draw_instance, 31, 30,  "GL_ARB_draw_instanced" ),
    FEAT(dual_src_blend, 33, UNAVAIL,  "GL_ARB_blend_func_extended", "GL_EXT_blend_func_extended" ),
-   FEAT(depth_clamp, 32, UNAVAIL, "GL_ARB_depth_clamp", "GL_NV_depth_clamp"),
+   FEAT(depth_clamp, 32, UNAVAIL, "GL_ARB_depth_clamp", "GL_EXT_depth_clamp", "GL_NV_depth_clamp"),
    FEAT(fb_no_attach, 43, 31,  "GL_ARB_framebuffer_no_attachments" ),
    FEAT(framebuffer_fetch, UNAVAIL, UNAVAIL,  "GL_EXT_shader_framebuffer_fetch" ),
    FEAT(geometry_shader, 32, 32, "GL_EXT_geometry_shader", "GL_OES_geometry_shader"),