amd: lower load_subgroup_invocation in NIR

Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32782>

src/amd/compiler/aco_instruction_selection.cpp

@@ -8139,10 +8139,6 @@ visit_intrinsic(isel_context* ctx, nir_intrinsic_instr* instr)
       break;
    }
 
-   case nir_intrinsic_load_subgroup_invocation: {
-      emit_mbcnt(ctx, get_ssa_temp(ctx, &instr->def));
-      break;
-   }
    case nir_intrinsic_ballot_relaxed:
    case nir_intrinsic_ballot: {
       Temp src = get_ssa_temp(ctx, instr->src[0].ssa);