intel/compiler: adjust [store|load]_task_payload.base too

Base also needs to be converted from bytes to words.

Fixes: c36ae42e4c ("intel/compiler: Use nir_var_mem_task_payload")
Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19409>

src/intel/compiler/brw_mesh.cpp

@@ -204,6 +204,10 @@ brw_nir_adjust_task_payload_offsets_instr(struct nir_builder *b,
       nir_ssa_def *offset = nir_ishr_imm(b, offset_src->ssa, 2);
       nir_instr_rewrite_src(&intrin->instr, offset_src, nir_src_for_ssa(offset));
 
+      unsigned base = nir_intrinsic_base(intrin);
+      assert(base % 4 == 0);
+      nir_intrinsic_set_base(intrin, base / 4);
+
       return true;
    }