aco: check instruction format before waiting for a previous SMEM store

aco: check instruction format before waiting for a previous SMEM store

Totals from 7 (0.01% of 127638) affected shaders:
CodeSize: 40336 -> 40320 (-0.04%)
Instrs: 7807 -> 7803 (-0.05%)
Cycles: 118588 -> 118344 (-0.21%); split: -0.23%, +0.02%
SMEM: 331 -> 339 (+2.42%)

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Fixes: 1749953ea3 ('aco/gfx10: Wait for pending SMEM stores before loads')
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4880>