Add missing writemask on TGSI_SEMANTIC_CLIPDIST writes.

If the OUT[] wasn't .xyzw, then the types wouldn't match and we'd
compile fail.  GLSL-to-TGSI always emitted a full vec4 write, but that
shouldn't be required.

Closes: #193
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>

src/vrend_shader.c

@@ -3736,7 +3736,7 @@ get_destination_info(struct dump_ctx *ctx,
                      else
                         snprintf(clip_indirect, sizeof(clip_indirect), "+ %d", dst_reg->Register.Index - ctx->outputs[j].first);
                   }
-                  snprintf(dsts[i], 255, "clip_dist_temp[%d %s]", ctx->outputs[j].sid, clip_indirect);
+                  snprintf(dsts[i], 255, "clip_dist_temp[%d %s]%s", ctx->outputs[j].sid, clip_indirect, writemask);
                } else if (ctx->outputs[j].name == TGSI_SEMANTIC_TESSOUTER ||
                           ctx->outputs[j].name == TGSI_SEMANTIC_TESSINNER ||
                           ctx->outputs[j].name == TGSI_SEMANTIC_SAMPLEMASK) {