freedreno/ir3/tests: Switch disasm test over to new decoder

freedreno/ir3/tests: Switch disasm test over to new decoder

Also, uncomment the `stc` test vectors (since the new decoder decodes
these properly) and comment out an instruction which looks suspiciously
like -6.0 in hex.

This also switches the parser back to `atomic.b.op` from `atomic.op.b`
which was a short-term workaround to make it easier for the legacy
disassembler.

Also switch the binary encoding for ldib to clear b0, because the new
disassembler warns about unexpected dontcare bits (which cases the
disasm to not match).

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7997>