radv: fix set_output_usage_mask() with composite and 64-bit types

radv: fix set_output_usage_mask() with composite and 64-bit types

It previously used var->type instead of deref_instr->type and didn't
handle 64-bit outputs.

This fixes lots of transform feedback CTS tests involving transform
feedback and geometry shaders (mostly
dEQP-VK.transform_feedback.fuzz.random_geometry.*)

v2: fix writemask widening when comp != 0
v3: fix 64-bit variables when comp != 0, again

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Cc: 19.0 19.1 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>