doc: add 'vec4' option in INTEL_DEBUG
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
diff --git a/docs/envvars.html b/docs/envvars.html
index 06aa0ac..e21b7c1 100644
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -163,6 +163,7 @@
<li>blorp - emit messages about the blorp operations (blits & clears)</li>
<li>nodualobj - suppress generation of dual-object geometry shader code</li>
<li>optimizer - dump shader assembly to files at each optimization pass and iteration that make progress</li>
+ <li>vec4 - force vec4 mode in vertex shader</li>
</ul>
</ul>