pan/mdg: Ingest new-style registers

pan/mdg: Ingest new-style registers

Switch to register intrinsics, using the helpers. Since our backend copyprop
chokes on non-SSA moves, we get better coalescing with this approach, hence the
small improvements to instruction count / cycle count in shader-db. Changes to
register pressure seem to be noise from iteration order. I'm not too worried.

   total instructions in shared programs: 1508444 -> 1508193 (-0.02%)
   instructions in affected programs: 42581 -> 42330 (-0.59%)
   helped: 482
   HURT: 41
   Inconclusive result (value mean confidence interval includes 0).

   total bundles in shared programs: 643023 -> 643136 (0.02%)
   bundles in affected programs: 16318 -> 16431 (0.69%)
   helped: 230
   HURT: 85
   Inconclusive result (value mean confidence interval includes 0).

   total quadwords in shared programs: 1125992 -> 1125600 (-0.03%)
   quadwords in affected programs: 125366 -> 124974 (-0.31%)
   helped: 507
   HURT: 351
   Quadwords are helped.

   total registers in shared programs: 90632 -> 90554 (-0.09%)
   registers in affected programs: 669 -> 591 (-11.66%)
   helped: 114
   HURT: 31
   Registers are helped.

   total threads in shared programs: 55607 -> 55600 (-0.01%)
   threads in affected programs: 20 -> 13 (-35.00%)
   helped: 1
   HURT: 7
   Inconclusive result (value mean confidence interval includes 0).

   total spills in shared programs: 1371 -> 1437 (4.81%)
   spills in affected programs: 44 -> 110 (150.00%)
   helped: 0
   HURT: 2

   total fills in shared programs: 5133 -> 5273 (2.73%)
   fills in affected programs: 84 -> 224 (166.67%)
   helped: 0
   HURT: 2

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23089>