glsl_to_tgsi: Set TGSI_PROPERTY_FS_BLEND_EQUATION_ADVANCED

In virgl, when fbfetch extention is not available but blend_equation_advanced is,
we didn't call lower_blend_equation_advanced. So we need to pass the blend value
to the host in order to recreate the shader correctly.

Signed-off-by: Elie Tournier <elie.tournier@collabora.com>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5516>

src/mesa/state_tracker/st_glsl_to_tgsi.cpp

@@ -6813,6 +6813,12 @@ st_translate_program(
             goto out;
          }
       }
+
+      if (program->shader->Program->sh.fs.BlendSupport)
+         ureg_property(ureg,
+                       TGSI_PROPERTY_FS_BLEND_EQUATION_ADVANCED,
+                       program->shader->Program->sh.fs.BlendSupport);
+
    }
    else if (procType == PIPE_SHADER_VERTEX) {
       for (i = 0; i < numOutputs; i++) {