aco/ra: create VCC-affinities during RA

aco/ra: create VCC-affinities during RA

instead of using register hints.

Totals from 88367 (65.50% of 134913) affected shaders: (GFX10.3)
CodeSize: 322492184 -> 322252912 (-0.07%); split: -0.08%, +0.01%
Instrs: 60615809 -> 60541260 (-0.12%); split: -0.12%, +0.00%
Latency: 557067980 -> 557009210 (-0.01%); split: -0.01%, +0.00%
InvThroughput: 109676757 -> 109674804 (-0.00%); split: -0.00%, +0.00%
SClause: 1939703 -> 1939924 (+0.01%); split: -0.01%, +0.02%
Copies: 4557567 -> 4487530 (-1.54%); split: -1.54%, +0.00%
Branches: 1941123 -> 1937453 (-0.19%)

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15408>