aco: Send MSG_ORDERED_PS_DONE where necessary

aco: Send MSG_ORDERED_PS_DONE where necessary

If the wave has set the Primitive Ordered Pixel Shading packer ID hardware
register, it must send MSG_ORDERED_PS_DONE once before the program ends.
It's also safe to send the message if the packer ID register hasn't been
set yet, therefore the message may be sent conservatively. For simplicity,
to ensure that it's sent on all execution paths after setting the packer ID
register, always sending it from a top-level block. This is required for
GFX9-10.3 POPS.

Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Vitaliy Triang3l Kuzmin <triang3l@yandex.ru>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22250>