Instead of assuming scalar alignment for an attribute, we can use the
required alignment of other attributes in a binding to expect a higher
one.

This uses the alignment of all attributes in the pipeline, not just the
ones loaded. This can create slightly better code, but could break
pipelines which relied on unused (and unaligned) attributes no being
loaded. I don't think such pipelines are allowed by the spec.

fossil-db (Sienna Cichlid):
Totals from 44350 (30.32% of 146267) affected shaders:
VGPRs: 1694464 -> 1700616 (+0.36%); split: -0.08%, +0.44%
CodeSize: 60207184 -> 58093836 (-3.51%); split: -3.51%, +0.00%
MaxWaves: 1175998 -> 1174948 (-0.09%); split: +0.02%, -0.11%
Instrs: 11763444 -> 11458952 (-2.59%); split: -2.60%, +0.01%
Latency: 70679612 -> 67062215 (-5.12%); split: -5.27%, +0.15%
InvThroughput: 11482495 -> 11362911 (-1.04%); split: -1.20%, +0.16%
VClause: 359459 -> 343248 (-4.51%); split: -6.36%, +1.85%
SClause: 422404 -> 419229 (-0.75%); split: -1.17%, +0.42%
Copies: 754384 -> 764368 (+1.32%); split: -1.74%, +3.06%
Branches: 197472 -> 197474 (+0.00%); split: -0.03%, +0.03%
PreVGPRs: 1215348 -> 1215503 (+0.01%)

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <mesa/mesa!9007>