pan/midgard: Add address analysis framework

pan/midgard: Add address analysis framework

Midgard has the ability to calculate addresses as part of the load/store
pipeline. We'd like to make use of this to avoid doing this work on the
ALU pipes. To do so, when emitting globals/SSBOs/shareds, we walk the
tree looking for address arithmetic to try to parse out something the
hardware can work with, letting the original instructions be DCE'd
ideally. This analysis is done at the NIR level to properly account for
some messy details of vectorization which we'd rather not poke at the
backend level. (Originally I wrote this as a MIR pass but I'm fairly
sure it was wrong.)

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3978>